Thanks for submitting your question to the Disney Parks Moms Panel! At present time, there are no mini-fridges available in the rooms at Disney's Port Orleans Riverside Resort. The reason is that Disney is in the process of replacing them in most resorts. I just made a quick call to your resort and a Cast Member advised that they have not been replaced. If you need one, you may place a special request, however there are no guarantees. I would recommend that you call Guest Services at 1 (407) 939-7675 and ask the Cast Member to add your request to your reservation.
Hope this helps! If I can assist you with any other questions, please feel free to send them my way!