I'm not sure there are protocols. When Little Caroline has needed to speak here, she has just come out and done it. Similarly in chat; in fact I have been known to switch mid chat - which must be confusing for some others! I wouldn't worry too much, Audrey; just let your littles come out and meet up with others here.
Little Caroline is about 9, and Baby must be 4 or 5 I think but I'm not sure.