How do you deal with people that don’t seem to want to work with you but have to?

I work for an international company. I work remotely in the states. the woman that is supposed to be my mentor doesn’t know how to coach. Our boss wants us to have a close working relationship as we are on the same team. This woman can sometimes come off very rude, maybe it’s a cultural thing? She’s told me in our meetings she doesn’t agree with our boss on how my background is of value, not in those words. When I ask questions she says things like “you should know this and if you don’t, ask”. I stopped asking because it always seems to be a bother. She asks me to help her and I’ve always been reliable and helped her when it fits into my daily schedule. Her urgencies are not my problem, especially when she comes at me one minute with how something needs to be done asap but then doesn’t communicate the full info needed to complete the tasks. No matter the circumstances and how much I send her the information she needs, complete the spreadsheets she doesn’t want to deal with, support her stateside, she just doesn’t seem to see me as reliable. I’ve come to find she gossips behind my back with some of my coworkers here in the states. She doesn’t even know me. I’ve told my boss there is no getting to know one another as she’s not interested. When I’m visiting the main office I’ve asked for a work lunch but she always says she’s busy. I just want to get my work done unfortunately I need to figure out a work balance with this person.