Howdy Angela!!
Disney's Coronado Springs Resort is such an amazing Resort! It's beautiful and offers so much for Guests of all ages! I know you will love your time there!
To be on the safe side, if you are able to, you might want to pack an air mattress and the linens that will be needed. It may not be necessary but if, by chance, they are not able to accommodate you, I don't want you to begin your vacation with challenges.
Depending on what type of room you are assigned to, you can request a rollaway bed once you arrive. However, due to the layout of some rooms, a rollaway may not fit.
I would suggest that you do 2 things to increase the likelihood that a rollaway bed will be available.
1. Contact Disney Reservations at (407) 939-1936 and ask the Cast Member to make a note on your reservation with your request.
2. When you are 10 days out from your check-in date, contact Coronado Springs at (407) 939-1000 and ensure your request is noted on your reservation.
This will not guarantee your request but the Cast Members who assign the rooms will do all they can to accommodate you.
If you are able to take an air mattress with you, you might wait to make your final request for the rollaway bed until you have visited your room. Once you are in your home away from home, you will be able to determine what would be best for your time at the Resort.
Thanks so much for your question and please let me know if you need any further information. Have a magical day!