Wily is very surprisingly good with kids. For some reason his "villain face" seems not to affect kids and Pokémon, and he doesn't talk down to children(mostly because his own development was so weird he doesn't see why anyone would).

Phillip is not great with young kids, if a bit too inattentive(takes him a while to learn the kind of focus and patience needed), but he's GREAT with teenagers and relates to them very well.

Mahra is great with them, both personally and professional. (She did manage to basically raise Wily from age 11)

Polly is good kids, but it really tugs on her heartstrings to see a child in grief, since it's also unusual.

Sivrit would be pretty bad with them due to having little patience.