I would do as Bookworm said and put her in a separate area and in a playpen so she can't get out. I have one child who sleeps less time than the others and after he falls asleep I put a few little (safe) toys and books at his feet so he can amuse himself when he wakes up. WE need our break and the children need their sleep. You are protecting the sleep of all the other children so it's your job, don't feel bad.