gift suggestion for preschool friend please

orangeluck

DD was invited to her first friend bday party for a preschool classmate at a bounce place and I'm clueless.  We don't know the child or the parents at all but I think going will be good for DD because she is so very shy but really loves physical stuff.  I'm assuming I would stay and it's not a drop off thing (right? for 3-4 year olds?), it's less than 2 hours.

We've never been to another child's real party (just family parties or small playdates where we exchange with close friends).  Any suggestion for a gift or what price range to spend?  Would a puzzle/book in the $10-15 range work for this 4 year old?