Skip Jaws. The rocking is pretty violent and can be very jarring depending on which boat you get (They all have minds of their own, I swear!) Once the ride has started, there's really no way for the skipper to stop the rocking short of an E-Stop, which is generally reserved for a man-overboard situation. Honestly, I would skip anything Universal recommends an expectant mother shouldn't experience. Yes, Maybe Universal is being overly cautious, but if it were my child, I would want to be overly cautious myself. Skipping those attractions doesn't mean you can't have fun! There are plenty of shows to experience, and certain attractions offer stationary seating/viewing areas (Shrek, Twister, and Jimmy Neutron among others.)
I hope you have a nice trip!