The issue in your exemple (it is an issue with the current system, definitely!) is probably one of the easiest to solve : Just "cast AOO" with the target "ogre" during Lae'zel's turn. You know the initiative order. If the baby was playing after the ogre, you would probably have "casted AOO" on both. If the ogre doesn't move, Lae'zel is going to attack the baby if he's moving.
Plenty ? You would probably have a bit less control and a bit more things to do during your turns (check or plan your reactions, eventually). But with a few more tools I'm not as sure as you are in the end, really.