I would buy for me, especially when you are talking about a couple times a year. They can have their privacy when they get home. It's only a matter of sleeping. We learned our lesson. Bought our 31' TT with quad bunks. We only have one child at home but thought she would bring friends along 3 yrs later not a single time did she bring a friend. Moved up to the class c. Much better for us all around.
If you are going to only use it a couple times a year, I would just invest in a couple nice tents. One for you and hubby and other for girls.
