Is a gender neutral baby gift appropriate as a Christmas gift for a couple expecting their third child?

My boyfriend’s friend and his wife are expecting their third child. They already have two boys ages three and one. I thought since they are being so kind to let me stay with them and my boyfriend for three weeks, I’d get them something for Christmas.

I don’t know the gender of the baby, so would a gender neutral baby gift be appropriate for their Christmas gift?
I have no idea what that will be. Suggestions are appreciated!