An Evil Stepmother in Real Life?

My mom died when I was 6. My dad remarried this older "Christian" lady to be a female role model when I was 9. I was immature at that time and didn't like her very much and told her so. She started acting aloof around me and wanted to have her own kid so she and my dad started going to some kind of fertility place and she eventually got pregnant when I was 11. That was when she got mean and everything but then I thought it was just hormones. Except she got nastier after the pregnancy and her parents made it worse by spreading rumors about everyone. Then we tried to have a sit-down talk with them but they just refused to see from our point of view. And so yeah she pretty much emotionally abused me and my dad for 2.5 years. Now things are getting better, but her parents are here again and my stepmom always acts mean when they're around because of this childhood she had or something. Can any of you give me some spiritual guidance on how to deal with this situation? I feel afraid whenever I'm around her and she still openly hates me (like purposely ignoring my presence and saying stuff "your daughter's a waste of my money" and "your daughter's a spoiled brat" to my dad...for some reason she never says that to my face???) I'm a Christian and I still believe that God has a purpose for all this so non-Christians please don't make rude comments about my religion. Thank you for reading all this!