My fiance is very close with 1 of his sisters, I have met her several times and feel like I know her pretty well. I want to ask her to be a bridesmaid, but he has another sister that is much older (in her 40's) and I've only met her once. They are not close and hardly talk, and he said she doesn't like being the center of attention. Is it ok for me to only ask the 1 sister to be in the bridal party?