Even if she saved your dad's life, she doesn't come off as trustworthy. I personally have dealt with my own shitty stepmother in the past. She used to try and get me to turn against my own mom by trying to implant the idea that she was being neglectful and abusive towards me. She abused my dad both physically and verbally, she used to beat my brother (not to the point of bruising) though she thankfully stopped when he was in kindergarten, she would call the police on my mom for all sorts of nonsense and had a strange rivarly with her, physically attacked my mom twice in a day, and caused a bunch of drama within our family and would play victim and act as though she's being forced into the middle of all of it with me.
She was a manipulative abusive piece of shit and recently my dad nearly ended up going to jail for a year thanks to her. Now we won't be able to see my brother fora while because it's apart of the set of agreements he must follow in order to stay out of jail. Now my dad won't be able to celebrate his birthday with his son. At the same time, she has gone out of her way to do some very nice things for him, but I still hate her.
Most people aren't just good or bad, instead they are a mixture of both. Your stepmother may have gone out of her wat to save your father's life but that doesn't mean you have to like her and trust her. You can acknowledge her good aspects while still not liking her. It doesn't make you a bad person. It's normal and completely understandable. You don't have to force yourself to like or trust anyone.
