So were they Children if the Forest on Bran’s side? They were there with the Wights when the Night King was defeated right? Or was that just a load of dead people?
Children of Forest lived in Westeros alongside man until man started a war. Children of the Forest were losing so they created the White Walkers. We then see them again at the three eyed raven and they all died (all 4/5 of them) when Bran got 'marked' by the Night King. We basically have very, very small snippets of information about the White Walkers and Children of the Forest at this point.
Hard to tell if they were part of the Army of the Dead, they all looked human to me.