Congratulations!!
As far as tips, I think it will depend 100% on how she is feeling. I had an incredibly easy pregnancy and other than crying hysterically through every performance of Voices of Liberty, I had very few symptoms to speak of. We live about an hour from Disney and visited often right up until the week the baby was born and I just skipped anything with a pregnancy warning.
Some are struggling with morning sickness at that point so you may have to just pace your trip if she is.
Advice for anyone visiting Florida in the heat, especially those expecting: hydrate! I drank water like it was going out of style when pregnant and realized real quickly that my usual plan of just stopping by QS for free water wasn't cutting it (I burst into tears waiting for free water at Electric Umbrella once) so we started bringing a huge water bottle and stopping often to refill it before I got desperate
Hope you have a great trip!