From Bulbapedia, the community-driven Pokémon encyclopedia.
The following lists all the possible Pokémon that may be used by Poké Kids in the Battle Tower.
Albert, Blake, and Robin
Alex, Dromena, and Penelope
Fero, Avit, and Katherine
Curon and Cadet
Agila and Laelia
Alan will Dynamax Vikavolt, Centiskorch, or Escavalier at the first opportunity.