Witz, if you need a few more hugs, I've got 'em!
Maybe I'm missing something here but I'm not following her logic at all. How does your refusing to make up with your family make you 'untrustworthy'? That doesn't even make sense! And I don't blame you a bit! You're an adult and it's your decision to make and nobody knows the situation better than you do. I'd be telling her too, it's NOT open to discussion - period! Don't allow her to guilt-trip you! Obviously she's getting to you or you wouldn't be having the reaction that you are! Please don't allow her to have that power over you!