I've generally written 3rd person limited omniscient, allowing myself into one character's head at a time. I may keep the same character for a few chapters (though I haven't pieced things into chapters yet, since I am writing scenes as they hit me), but I wait until a good chapter/scene shift to change points of view. I have a story where both boy and mother are vital characters and it's been working so far until this latest scene. By the time I finished writing, I had been in both of their heads and thoughts were coming from each of them. I'm concerned this will be confusing to my reader, but it almost seems important in this particular scene to see how each character responds internally to the change of events.