There is a clean mall maintained public restroom between Claires and Rue 21, there is another inside GAP and there is one inside VF towards the center rear of the store. You can also get Mall Coupons at VF for $5 cash if you come when the mall office is closed. (like weekends). These are the only bathrooms I am certain about.

I am from Oshkosh so I am kind of biased of our area mall. You will not regret it as most of the stores provide you great service and awesome bargains. Gap is our favourite as they have really good bargains. Old Navy, Aerospostale are great too. Nike, Under Armour, Skechers, Famous footwear outlet are great for shoes. For kid's clothing OshKosh B'gosh, Gymboree Outlet, The Children's Place Outlet would you give you ample selections and bargains. Please do not hesitate to contact if you have any more questions regarding Oshkosh. Enjoy your visit when you come to Oshkosh. If you have time try to take the kids to Menomanee park. They 'll love it,