My four year old has this backpack (...)My kiddo barely uses this backpack. On her small frame (fits size 5 now), it's very akward for her to walk with it on, because the book ends up being wider than her body. This causes her to get stuck in doors and tight spaces. I usually just end up holding the thing for her, don't know about your kid but mine hates wearing backpacks for long anyway!The design is hard on their bodies because the book is so flat, and with extra books in the backpack it's very hard against the back.The backpack doesn't hold many of the books, I can fit maybe 2 in there. (...) Don't buy this, it'll just sit on the shelf!