Welcome to the Disney Parks Moms Panel "home", Lauren! Congratulations on your pregnancy - babies are the most exciting thing.
Pandora - The World of Avatar is so much more than just
Avatar Flight of Passage. The theming of the land is absolutely stunning, especially if you visit in the evening, when you can get the full effect of the bioluminescense. The
Na'vi River Journey is like drifting through a world of wonder, with swirls of enchantment at every turn. It's stunning.
The recommendation for Avatar Flight of Passage is that expectant mothers should not ride. While I have personally ridden this attraction and don't find it to be particularly bumping or jarring, there is a lot of movement and the feeling of deep dives. The seat itself also has you pinned in pretty well, in order for you to be safe on the journey, and I would say you couldn't rule out a bit of a bump in your "bump" region as you take flight.
You might instead browse the Valley of Mo'ara. Take a stroll through
Windtraders, where you can purchase your own banshee (it would make a great nursery decoration for a fantasy themed nursery!), or grab a bite to eat at
Satu'li Canteen - hands down, the best counter service restaurant in my opinion.
I hope you get to enjoy an absolutely magical time on your upcoming visit.
Anna