Anti-confrontational FTM. Advice needed

Esther • I’m better than horrible. EMT and Respiratory Therapist

So my dad texts me the other night and drops the bomb that his mother is going to visit on Tuesdays while my mom is watches him. (I work and my mom watched him m-w.) I’m upset because I wasn’t asked, I was told like I’m a child still. And they know I have issues with it because she sexually abused my dad and the my brother. (my dad never confessed to my mom what happened to him as a kid until my brother said what was happening to him.)

He keeps telling me that she’ll never be alone with him and that she’s still family. It’s also been mentioned that she’ll probably die soon. I’m really trying to stick to my guns but I’m really anti-confrontational and I don’t know how stubborn I’m being. I mean, he’s never going to be alone with her so should I just leave it be and let her seen him as long as she’s supervised? Still mad that plans were made behind my back though. It makes me feel like I can’t trust them and needs a new sitter,but I can’t afford daycare.

Please help me!