Fears of a little Saphrin

Most nights it is a struggle to get Saphrin to go to bed. She is way to hyper. Matt was putting her to bed and this is what insued:

Matt: It is important so her body could rest and her bones could grow bigger.
Saphrin: (she hinds under the blanket and then pops her head out with a sad face)
Matt: What is wrong?
Saphrin: I don't want to grow big and tall.
Matt: Everyone grows. Sophia's growing, Estin and Keelen are growing...
Saphrin: Is Morgan growing? is Marissa grow?
Matt: Yes.

I can almost hear there conversation right now. Matt having the little meek voice when he says it. He does great with the kids. I can't come up with stuff like that to tell the kids. She is just growing up. Just don't tell her she will have nothing to do with that.