I thought you were talking about euthanasia!!!!
I agree with the other folks, pups need their rest and you are right to ask your daughters not to hold the pup all the time. It may be good to have a designated play time during the puppy's daily active period, i.e. say from 8-9am, and 5-6pm where they can romp to their hearts content, and then anytime before or after, leave the puppy alone. Just a suggestion!
Good luck!