Most any ride that is not "roller coaster like".
no mountains, no rnr, no mission space, no tower of terror, no everest..stuff your 2yo can't do anyway.
I do think you could feasibly go on test track if you wanted to. It is nothing but a car ride--disney style. And I know there are pregnant women driving in convertibles on the freeway

.
I would even venture on Kilamanjaro safari if you are up to it though it does get very bumpy hence the advisory.
Kali River rapids may be out b/c that is kind of rough--but most everything else you can do (and there is a lot though it doesn't seem like it after all of that

).
Up for you enjoyment: All of Fantasyland, all of adventureland, a little bit of tomorrowland (for the race cars--have a member of your family drive safely behind you--I always do that b/c of my neck and it prevents any accidental rear endings as hubby makes sure to maintain several car lengths so even if he gets hit, he won't get me)....All the animal kingdom shows, all the non-rides in epcot, and most everything in MGM except the two rides I mentioned.
Plenty to do for fun when you are 5 months pregnant and vacationing with your 2yo.

Just keep to what she is allowed to do and enjoy! (except goofy's barnstormer--she can do that....but you shouldn't).