imo i think mari would be a sorcerer but keeps a dagger/bat on her just in case.. she would have been a warlock but she couldnt convince some higher power if she tried :') and for uhhh kel id say bard, and he'd bring a make shift piano-guitar with him everywhere (though he MIGHT bring a bow n arrow as a weapon)
for tam i think she'd be a bard aswell (because shes literally in the school band) and i dont think she'd bring any weapons with her, shed probably have a guard dog of something (a chihuahua to be exact :D)
and for qiu imma say paladin. Now hear me out THEYRE ALWAYS THOUGHTFUL OF EVERYONE AND STAY TRUE TO THEIR WORDS(ish) or perhaps theyd be a warlock i dunno :( as for weapons maybe a sword?