I got some very nice "Will you be my bridesmaid?" cards from Etsy.  I am asking my fiance's sister (who I have met once) and cousin (who I have never met) to be bridesmaids.  They both live out of state.
I can't figure out what to write on the cards!  I've gotten as far "We would be honored if you could be a part of our day."  What else do I say?  And how do I say "let me know if you accept" in an eloquent way?