Hello Mary Anne and thanks for bringing such an important question to the Disney Parks Moms Panel.
Firstly may I offer you my personal congratulations on your dear daughter-in-law's pregnancy, I can only just imagine how excited you must be feeling about the arrival next yEar of your darling new little Prince or Princess!
To the very best of my knowledge there isn't a list as such of
prohibited Attractions which expect mothers should avoid, however these
Disney Attractions do include signage which clearly states there are physical considerations for pregnant ladies.
It's always worth remembering that all Cast Members at Walt Disney World Resort are simply
Wild About Safety and should always be your ultimate guide when considering entering an Attraction, Experience or Show as they can offer Guests their very best safety knowledge and up to date advice.
My personal advice would be for your lovely daughter-in-law to consult with and follow the medical advice of her physician before arriving at Walt Disney World Resort.
Wishing you a more than magical December visit to Walt Disney World Resort where I'm sure you'll create some unforgettable
Disney Holiday memories together.
Have a great Disney day.
~ Jane