The who part.
Now, this probably seems self-explanatory. Of course, the audience for children's time would be children, right?
Well, if your goal is to dedicate a part of the service for the purposes of nurturing the children in the congregation, then yes, the audience should be the children. The tricky thing here, if you listen carefully to a lot of children's times, is that quite often we co-opt children's time and use it to teach adults. I know, I've done it (unintentionally of course!) myself. Instead of speaking with, or to the children, we speak through them. Pay attention to your eye contact when you're leading. Are you looking into the eyes of the children, or the eyes of the adults in the pews? Do you make casual references or humorous comments that only the adults understand? When a child makes a comment, are you able to respectfully affirm their contribution and engage them in discussion, providing a model for the rest of the congregation, or do you laugh along with the other adults present at the child's "cute" comment?
During children's time we, as leaders, have the opportunity to share the biblical story and engage children in conversation that connects their story with God's story. We have the opportunity to draw out the spiritual yearnings that are already present in each child, and in doing so, show them that the spiritual life is precious and worth nurturing. And we have the opportunity to model for other adults in the congregation how we can all show respect for children as spiritual beings. We do this, not by teaching adults during children's time, but by engaging children. And I'm not saying this is easy, it's actually a pretty counter-cultural practice.
If we want children's time to be for children, then we need to engage them specifically. The content needs to be for them and our attention should be on them. Sure, adults can listen in and learn something, but essentially, they need to sit and wait patiently and respectfully while the children have the opportunity to meet God in their own way. I have occasionally heard adults complain that they don't like children's time, that it interrupts their worship. All I can say to that is, if the rest of the hour-long service is basically for their benefit, then at least these 5 minutes should be held for the kids.
If, however, children's time at your church (as mentioned in the previous post), is a time of story-telling in which children are invited to come forward, but the time is really for the entire congregation, then the audience is much broader and your content and attention should reflect that. In congregations where this is the case, most often the rest of the service makes space for children to participate as well.
Just some thoughts on the "who." :)