moh dilemma

Complicated issue here so please have patience. I have a younger sister whom growing up we were never really close. I have a cousin whom I watched grow up over the last 10 years ( I moved from MI to AZ which is where they lived) and initially thought about making them co- MOH’s. When I first got engaged and told my cousin, immediately she sent a text that if I made her a MOH, she doesn’t have any money to do anything (she’s 21). That annoyed me a little bc it’s not just about money but I also feel her mother (my aunt) said something. Long story short my mom and my aunt are currently not speaking to one another. Since I live in same state as my aunt, the couple of times we’ve gotten together she’s been so negative. I love my cousin but at 21, she basically follows what my aunt says. Idk if I should skip the drama and just go with my sister or go ahead and try to make them co-MOH’s.