Being a native, we do not venture into the parks in July - but - you can still have fun. It is like packing for a cruise - write down everything you want to do and then cut the list by half so you can spend the afternoons in the shade and inside! So, if the trip if for relaxation - and not to make the most of the ticket - here's some suggestions:
After lunch (by 2:00 at the latest) head to the pool, cool shower and then a nap - and remember that all important sunscreen, hat for the parks, long-sleeves if she is fair skinned and lots and lots and lots of water....At least one glass of water for each glass of beer will do it...Then you are rested for the evening which should not begin before 5:00....
We love looking around the hotels, and that is fun for the afternoon if you don't want to nap....Downtown Disney is out because of the walking and heat. And forget the parks. Even the Bar at Tusker House becomes unbearable after May...As for the water parks - they tend to close (Full Up) before noon...at least on weekends.
Anyway - Good Luck.