People have different needs that might not be obvious to others, so may need facilities they may not seem to at first thought.
Here's some more information to help the OP decide what options there are.
All restrooms have at least one handicapped stall (ADA requirement). The smaller handicapped stalls may be too small and don't have a sink. They also have nothing for disposal except a small wall trash container (may not even be big enough to contain a pull-up).
There is usually a larger handicapped stall that is large enough that a wheelchair will fit inside. The older ones are just barely big enough for a wheelchair and not be large enough for changing a 5 yr old.
As bathrooms are being renovated, they are bringing those larger stalls up to the newer ADA guidelines, which include more space and a sink. Those also have a trash receptacle that is larger. They are still stalls though and may not have the amount of privacy you want for changing a 5 yr old. But, not all restrooms have been renovated yet.
There is sometimes a wait for the Companion Restrooms because of the amount of time people using them need and there are only about 6 per park, so are sometimes not convenient to where you are. Some locations are pretty visible, but take a bit more looking to find.
If you need to lie your child down, First Aid is really your only choice. They have private rooms with cots - just let them know what you need do they can send you to a room that meets your needs.
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