Stacy Holmes used to be a resident in Room 504. She was Megan's mother and Greg's lover.
Although the player doesn't get to know Stacy very well throughout the episode, she appears friendly and doesn't seem to wish Sal any harm.
In the video game "Seeking Providence" in Episode Two, she appears as a sprite in chapters 3 through 5. She is consistently portrayed as a loving and caring individual who is willing to go to great lengths to ensure her daughter's safety. This is showcased when she participated in Mrs. Rosenbergs scheme to disrupt the ritual that would likely summon Red-Eyed Demon.
It is also hinted throughout the game that she turned to the bottle for comfort when her husband became increasingly violent as he got more involved with the Devourers of God.
She formally appears grotesquely skewered on a mattress in her apartment. She has long purple hair and is wearing a blue tattered dress covered in blood. She has puncture wounds all over her body and it appears that her throat was ripped open, leaving her unable to talk, unlike Mrs. Sanderson who speaks through the slit.
Details of Stacy's life are sparse and can only be found throughout the games in the Super Gear Boy, what follows is what is given thus far.
When Stacy was young, she quickly became enamored with an equally attracted Luke Holmes. Their happiness did not seem to last beyond their marriage and the birth of their two daughters. When Luke became involved with the cult of God Devourers, Stacy became concerned with her husband's increasingly erratic behavior and was even broken to tears in the cult's church where she was to be found by a concerned Gregory Montague who offered comfort for the days to come.
An unknown amount of time later, Stacy gifted her daughter with her own mother's necklace of a cross. Inside Addison Apartments, Stacy partook in the schemes of Alyson Rosenberg to put an end to the ritual that would bring the cult's vision into fruition. After successfully cutting the power she is last seen saying that she prayed that their mission would yield success.
She was last found slaughtered in her bed in a mass murder-suicide at the hands of her distraught husband under the influence of Red-Eyes.
Stacy briefly meets Sal as a skewered ghost in room 504 and doesn't speak a word towards the inquisitive young male.
After the absence of Red Eyes, she seems to have loosened up a bit and is willing to play with the ghost of her daughter.