Sorry for my English, I hope the whole thing is going to be somewhat understandable. I'm also very angry atm, so forgive any mistakes. My BF (male, mid-thirties) has a daughter G (10) with his ex-wife, T. The ex-wife is fighting a very aggressive form of brain cancer.
Now, a bit of back-story. T and I never did get on well. I met my BF while he was in the proceedings of their divorce, and I think she's always thought we had an affair long before then.
She hates me a lot, and so does G. I've been called a home-wrecker, a slut and other nice things ever since I first met them.
Now, my BF is usually very quick to shut down their bullsh*t, but he adores his daughter and still cares about ex-wife (they've been together 15 years, and been friends since their childhood).