I have a best friend who I want to be my MOH, but she lives in Des Moines, and I (and the wedding) am in Kansas City. My older sister lives in my area, and I would like her to be MOH also. Mostly because she can do the stuff that my best friend can't because she is so far away. I have asked both to be a BM so far, but haven't specifically said "MOH" yet.
What are your experiences with/as OOT MOHs? I don't want to make it hard on her, have her feel like she HAS to drive out here at every little thing. I basically don't want it to burden her. She was a MOH for her sister while we were away at college (about 2 hours from home) and I remember her telling me it kind of sucked because of how far away it was. I want her to be one of my MOHs but don't want her to be pressured into doing anything she doesn't want to do, and I don't want her to feel like she did with her sister.
Is this something I can talk to her about and tell her my concern? We act like sisters and love each other so I know she won't be mad, but I want her to be comfortable. Is it rude to talk to her about it? 
How would you go about it? Any advice will help, thanks!