Sorry, with the above comment I just assumed too much I guess. Are you in this situation? Is that why you asked? Not trying to be too nosy...
I guess I just don't understand why the new member in this situation would be seeking to be excused from the sleepover. It sounds like she just doesn't want to do the sleepover and is using her husband as an excuse. Being married shouldn't affect the pledging process in any way, really.