J.R.
Hi A., my name is J., I have a almost 4year old and almost 7 year old. I just ordered their backpacks from LLBean, I read great reviews on it and have a friend whos daughters has had their packs for 3 years and it still looks brand new. LLBean also have a smallpack specially made for 4 year old children and up. The website is LLbean and then go to luggage and click on book packs. It is worth it.
Good Luck