Penguin fan refers to the blonde girl (who will become one in a later strip (around 8 or 9).

I don't have any nicknames for the two other characters.

I didn't expect Diva to start posting Zookeepers outside of Patreon, but I'm pleasantly surprised.

NotWhatISignedUpFor said:

I didn't expect Diva to start posting Zookeepers outside of Patreon, but I'm pleasantly surprised.

Diva posted an announcement about it last week (the same day that the series reached 100th image on patreon).

I guess Penguin Keeper is the Clumsy Counterpart of the group.
The Penguins accept and love her like the Ducks love and accept Clumsy Nun.