Mother complaining about father

My mother left my dad and is four kids when my youngest sister was 9 months old. She disappeared for about 7 years. Never heard from her or nothing. The past 20 some years she came in and out of our lives and has been addicted to meth and heroin for those 20 years. She is homeless but now staying with my grandma. She has been clean expect she drinks cough syrup like no other which messes her up bad.

Anyways, she is constantly complaining about my dad to me. Telling me he was controlling and that’s why she left. She says he never let her do anything, threw away her clothes, makeup etc. she’s trying to turn me against someone who raised me and my siblings alone, with no help from anyone, not even state assistance. I told her once that I just don’t need to hear it, there’s no reason to tell me. Well she keeps on wnd on. Is it wrong to block all communication with her? I don’t need this extra stress. I just had a baby and am going through pp depression as well. I feel after tell her once I don’t need to tell her again and honestly she has no right tryin to turn me against my father