Anonymous wrote:For all we know, the SIL only invited OP out of a sense of fairness and etiquette and would just as soon she didn't come.
That was my thought as well - especially if the other attendants are close in age/relationship. If it's DH's sister then you can find a nice way to get to know her otherwise. If it's your borther's fiancee, welcome her to the family in another way. I think attending a shower is more important than a bachelorette (and even that doesn't have to be reqired if circumstances prevent)