Welcome back to the Disney Parks Mom Panel, Larksana! Thank you for bringing us your question.
From your question it sounds like you will be staying at the
Campsites at Disney's Fort Wilderness Resort. This is an amazing facility. You will definitely never stay at a more magical camping resort. When roaming the resort don't forget to stop by the
Tri-Circle-D Ranch where the horses of Walt Disney World are stabled.
My whole family are huge fans of camping. We started tent camping when my daughter was very young. While the size of the tent will be a determining factor, I would think a pack 'n' plays would fit most tents without any issues. If you are looking for something a little more sturdy I suggest consulting the camping experts at Cabela's, Gander Mountain or Bass Pro Shop. They are some of our go-to places for camping equipment.
I hope this helps with your planning, If you have any other questions please come back and see me.
Wishing you a magical Disney vacation and a pixie-dusted day.
Sue N., IN