Crazy Grandma! Please help!?

She is either, a very manipulative person or has low self esteem (maybe she just doesn't know, a bit ignorant if i may say), you need a big load of patience and try talking to her, maybe is better if you do it with someone else there, could be her son or husband, so they can be the witnesses because surely she will change what you told her and use it against you (ie: like when she said that you disrespect her), if you still think is a culture thing, do a bit of research of her culture and understand why she is acting like that?... some old people aren't as flexible as us to understand other cultures and differences, and only see things their way and want everybody to be like that.