Monica Bratton is the aunt of Betsey Parker.
When Dell died, Betsey went to live with Monica. A few months later, Monica brought Betsey to the practice, saying she couldn't keep her. She hadn't had kids because she didn't want them. She initially took Betsey because it was the right thing to do, but she couldn't keep her any longer.
She is Betsey's aunt. It's unknown through which parent she is related to her.