Just a matter of time I guess. The first thing is what specifically she doesn't like about it. There isn't much you can do til you know that. Is she worried friends might be leary about it? Is she concerned about attention from other females? Does she think it's just too weird where you live? Find out the specifics and then you have a direct point to deal with.
When I started my wife thought, and still thinks, it was kinda off the wall. She gives me looks of amused tollerance mostly but I noticed when we go places she stays very close, letting other women know I'm taken Her position is really that as long as I look somewhat tidy and reasonably clean it's my choice to wear kilts or not.