In The Comics:
Dorothy McConnell, Patricia Walker's mother, was the in-universe writer of the Patsy Walker comics (referencing the real life Patsy Walker comics of the 1940s) loosely based on her daughter's teenage years. She amassed a media empire on those comics, whose portrayals the real Patsy grew uncomfortable with. At her death bed, she's offered returned youth and a cure for her cancer by a lesser demon who served Mephisto of Marvel comics canon, in exchange for Patsy's body, but she's thwarted by the Defenders, leading to her timely death.
In The TV Series:
Dorothy Walker is Trish Walker's talent agent and abusive mother, who put Trish through physical and emotional tortures in order to mould her into a superstar. She takes Jessica in as a PR stunt, but is eventually cowed by Jessica's super strength into leaving Trish alone, or at least becoming less controlling of her daughter's life. Trish eventually contacts her for information on IGH, which she gives in exchange for more of a relationship with her daughter. She becomes more involved in Trish's life later in the series, despite still being manipulative and toxic. She's played to delightfully hateful effect by Rebecca De Mornay.