I find my brother toxic so I am no contact with him. However, I am a Christian so I have (over time) forgiven him and will pray for him when I think of it - but most of the time I don't think of him. My mother still loves him because he is her child but she has not seen him in years. She does talk to him on the phone every few months.
It is not my place to dictate my mom's relationships to her, but I have told her that if my brother ever comes to visit, he must pick her up and drop her off at the house - he is not allowed inside. This is to protect myself, and Mom understands.