How young is too young to start having sleepovers for the kiddies? or how old is too old?My daughter is 5 y.o?

I think a sleep-over is a great idea especially for daughter's friends; I think 5 yrs. of age is a good age, any lower than that might be clified as baby-sitting(other than if it is family), and sleep-overs are great up thru her teen-age years.