@AdamJames if there are no other diabetics for generations either way then I think that covers genetics.
Only if you are angry and want to simplify things to help give yourself ammunition to judge your mother poorly. I'm sorry you don't have a good relationship with her, and I'm sorry you have T1.
But to be open-minded, I think we have to acknowledge that all we can be sure about is whether our parents, grandparents etc have been
diagnosed with diabetes. And even then, we can't be sure about that. I know my mother is diabetic, and I strongly
suspect my father was diabetic, but he never talked about stuff like that and I didn't live with him. And even if by some unusual means you could prove that nobody in your family has ever been genetically susceptible to T2, that doesn't mean your mother isn't. She may not have
inherited susceptibility, but that doesn't mean she doesn't have genetic susceptibility.
Also, I'd love to hear a definition of "over-eating". Again, it may seem clear-cut if you are angry. But if you want to come up with a definition that everyone can agree on, I think you've got a hell of a task on your hands.
I'm only making these arguments to make a general point that it doesn't hurt to be a bit more open-minded.