"Look at all the pretties my little girl has given me!" - Marguerite Baker, Resident Evil 7 (Daughters)
Marguerite was the matriarch of the Baker family, which consisted of her husband, Jack, and children, Lucas and Zoe. They lived on a large plantation in the Louisiana swamps, comprising a mansion and an older house, with mines and a pier nearby.
In 2014, the Baker family encountered Mia Winters and Eveline, who had been washed ashore after being shipwrecked, and decided to take them in. Unbeknownst to them, Eveline was a bio-organic weapon who possessed mind-controlling powers and was obsessed with having a family of her own.
Under Eveline's control
Eveline slowly infected both Mia and the Baker family with her mold. Marguerite consulted a doctor, who advised her to come back for further testing, as they had found mold on her skull during an x-ray. She planned to return to the doctor, but Eveline's infection would consume her before she could, and the newly possessed Marguerite would now view her infection as a "gift". She hid a D-Series Arm in Eveline's room to keep it safe, as it could be manufactured as a serum to eliminate the "gift" in a victim's body.
Her descent into madness can be gleaned from her notebook, the pages of which are scattered throughout the house. As a result of the infection, Marguerite gained the ability to produce and control mutant insects that hatched from Eveline's mold.
As the infection's hold over them strengthened, the family withdrew from community life completely, causing the locals to declare them dead and label sightings of the infected family members as supernatural phenomena. In actuality, Marguerite and her family were capturing people and turning them into Molded, which would add to the "family" Eveline wanted. They kept a list of the people they killed and turned, as well as newspapers reporting the dramatic increase in disappearances.
The family also turned to cannibalism, with most of the food Marguerite cooked being human body parts harvested from their victims. Zoe fled the house and hid out in the family trailer, where she guided kidnapped victims to escape. Marguerite and the family were aware of her "betrayal", however, and began antagonizing her.
In June 2017, three years after the arrival of Eveline, the American TV paranormal investigation series Sewer Gators investigated the house as a possible episode, resulting in the murders of producer Andre Strickland and presenter Peter Walken. The crew's cameraman, Clancy Jarvis, was shackled to the bed in Jack and Marguerite's bedroom while Marguerite welcomes him and forces him to eat their food, as she plans for him to join their "family". Clancy manages to uncover the puzzles around the room, but in the process caused loud noises that forced him to return to the bed as the Baker matriarch returned.
Marguerite would bring more food and would become more antsy as Clancy refuses to eat the food, as the latter had been using the utensils in his escape plan. Eventually, Marguerite returns to the bedroom where she realizes that Clancy had broken out. Clancy lunges at her and stabs her throat, which incapacitates her as she screams insults at him while he escapes.
Ethan Winters, Mia's husband, arrived at the Baker house a month after the incident with the Sewer Gators, after Eveline had sent an email message disguised as Mia. After encountering an infected Mia, Ethan was captured by Jack, and had his severed hand stapled back on by Zoe. Some time after this, Mia escaped captivity and attempted to flee from Marguerite, but was spotted by the infected woman, who was also aware of Mia's collusion with Zoe to escape. Marguerite pursued and eventually managed to corner her in a crawlspace in the old house, but Mia videotaped the event, and the recording would later be found in the mansion by Ethan.
Later, she prepared a dinner to "welcome" Ethan into their lifestyle, but became enraged at him and stormed out, spewing insults when he spat out the human body parts that Jack attempted to feed him. The meal was then cut short, however, when a deputy called, and Marguerite left with the rest of the family to answer the phone. After Ethan took the chance to escape, he discovered Mia's videotape and learned of both Marguerite's abilities and the layout of the old house.
When Ethan entered the second house in search of the D-Series Arm which could create the serum, Marguerite appeared once again, continually attacking him with her bugs as she stalked him throughout the old house. Eventually, she appeared at a door and demanded that he "stay the fuck out" before slamming it and presumably sending her insects after him. Unlike her husband, Marguerite attempted to stay as quiet as possible. Eventually, she trapped Ethan in a hole and sent her insects after him, but Ethan managed to fight off the insects and severely wound her, causing her to fall into the hole. She clung to her lantern, however, summoning a swarm of thick, cockroach-like insects to cover her and damage Ethan if he remained with her.
Ethan discovered that in order to access the second floor of the house and retrieve the arm, he had to retrieve Marguerite's lantern. Upon returning to the hole, he discovered that Marguerite had regenerated, but with grotesquely elongated limbs, causing her to resemble an oversized insect. He tracked Marguerite to a greenhouse, where Marguerite attacks once again, crawling along the walls and summoning insects to attack Ethan. However, Ethan managed to spot her weakness - a large hive in her crotch. After a long, tense battle, Ethan killed Marguerite and her body calcified and crumbled to dust, allowing Ethan to retrieve her lantern.
When Marguerite died, all of the insects she had spawned died as well. Jack, who mutated into a massive creature under a combination of both the mold and the regeneration ability granted by Eveline, later found out about Marguerite's death, and while fighting Ethan at the boat house proceeded to sob and say her name. While Ethan was cocooned later by Eveline, he saw a vision of Jack, who reveals that his family, including Marguerite, used to be good people. He then pleaded with Ethan to "free" his family from Eveline. After Ethan killed Eveline, he acknowledged that the Baker family were simply victims of Eveline's possession - as much victims as he and Mia.
Marguerite was once a caring, dutiful and traditional aged housewife who became twisted under Eveline's "gift", becoming a demented and psychopathic shell of her former self. Even when she initially became infected by Eveline's gift, she showed some hints at her prior nature, where she tells Zoe to come out of hiding in a gentle manner to meet Eveline (a noticeable contrast with her treatment of Mia in a similar situation later on where she was very hostile even when she tries to find her), and will noticeably hesitate to harm Zoe and even fight off Eveline's control long enough for Marguerite to give Zoe a key to the family car so the latter can find help.
Marguerite still attempts to treat her "guests" with care, only to serve up rotting food and Eveline's corrupting gift as meals. When her food is refused or she is challenged in general her sweet facade drops, revealing a violent and unhinged individual who threatens in the most disturbing ways imaginable. In some cases, she even reacts violently towards an individual simply to take her anger out for an unrelated event.
Marguerite lives in a delusion where she is convinced she is being the best she can be, and as such cannot understand why her precious guests refuse to eat or constantly try to escape. This only worsens her rage, complete with psychopathic fits as she hunted for Mia while screaming about the ungratefulness of her guests.
In the latter stages of her illness as she began to embrace Eveline's "gift", Marguerite began to adopt a darkly religious outlook in private affairs, making a "shrine" out of the D-series cranium briefcase, accepting the D-series arm from Eveline as a "gift of fortune" and and threatening horrible retribution on anyone who dared to touch these gifts, even her own daughter.
She also seems to have a huge fondness for bugs, at least post-infection, to the extent that she takes offense at anyone using phrases that infer bugs get hurt. This is implied by Jack Baker when, while stating his intentions to "squish [Ethan] like a bug", he then worries about whether Marguerite heard him say that.
Out of all of the Baker family members, she is the most visibly inhuman upon receiving Eveline's "gift", sporting demonic eyes and gaining the ability to control mutant insects. Belying her frail appearance, Marguerite possesses superhuman strength and speed. Her speed is demonstrated by her hunting down an escaping Mia Winters: Upon detecting Mia, she is capable of outrunning her, and also proceeds to lift her up by the neck, and later dragging Mia by the legs with minimal effort in the crawlspace at the end of the video. She also demonstrated a similar speed burst when, after Clancy taunted her after she discovered he was missing from the bed, rushed into the nearby room and proceeded to lift him up, although Clancy proceeded to temporarily stun her by stabbing her in the neck. She also has the peculiar ability to control bugs, ranging from bees to spiders, when she fought Mia's husband Ethan in attempt to stop him from entering her "shrine" room, via use of a lantern.
Like the rest of the Baker family, she possesses the ability to regenerate from damage, although she is far from invincible. When stabbed by Clancy, she only reacts with irritation, although she does struggle in trying to get the knife out of her. When severely wounded by Ethan, she was covered by insects and later appeared in a greenhouse with massively enlarged limbs, apparently having fused with them. In this state, she gained the ability to crawl along walls like an insect and would use this ability to ambush Ethan. More disturbingly, her lower abdomen becomes a swollen insect hive which she could discharge swarms toward Ethan, but would cause considerable pain to her as a weak spot if Ethan successfully damages it. Even prior to her transformation, however, she can partially morph by having a centipede-like creature emerge from her mouth. She demonstrated this first to Zoe in an attempt to show off Eveline's "gift", and later if she catches Clancy out of bed.