Do you often go for the low blows like that? You’re not a very nice person.

It was not intended as a low-blow. I thought was a logical conclusion based on the fact that you seem to be utterly opposed to OP's mother and sister and that my stance that OP should have a plan that she reviews with her support network (that may or may not include her mother), and that plan must consider OP's mother if she plans to stay with OP's mother I must either be her mother or sister.

I apologize that that came off as an Ad Hominem Attack - re-reading my post your response is totally valid. I was misguided when intending it as supportive comment, and even in the best possible reading it is... caustic. I can edit or delete the comment if you would like.

Back to our AITA disagreement: you could be right and that OP's mom & Sister could be horrible people. I REALLY hope you're wrong and that OP and her family can come together to find a 'happy ending,' or... at least a middle ground that everyone can be satisfied with.