Congratulations and all the best Betsy!
I absolutely can not WAIT to hear how your wedding is going to absolutely blow your FSIL's away. I actually feel a little sorry for her (well, no, actually I don't!) because I know you are really going to shine and your wedding will be PERFECT! I'm dying to hear how it goes, but in the meantime, you have a fabulous time! Don't think about her wedding, just focus on you and your day and marrying the man of your dreams. Safe travels!