Margaret Shakur is Ricky Underwood's adoptive mother, originally his foster mother, and Ethan's foster mother.
Unfortunately, she and her husband, Sanjay couldn't have children of their own, so they opted to foster children when they can. Margaret has always been there for Ricky in his time of need.
When Ricky was in foster care, he traveled from one home to another living with people he barely knew and people who didn't care for him until he came to live with Margaret and Sanjay Shakur who helped him a lot. They provided a comfortable home and food for Ricky.
Margaret is a social worker and helps children with a bad background. When she met Nora Underwood (Ricky's biological mom) and looked into her situation and after finding out that she was a alcoholic for a long time, but was sober for nearly two years, she helped her by letting Nora stay in her home.
When Ricky asked Margaret to act like Nora's mother, she tried to do that because she cares for Ricky like her own son although Ricky already thinks of her as his real mother.