Kiyo is definitely getting paid, guys. But there might be a large number of reasons she doesn’t seem to have a lot of money.
In Japan, wages may be less if the company you are working for provides room and board, but Kiyo may also be expected to pay back her time where she studied to be a Maiko (this is why the maiko only get pocket money too instead of their full wages, when they become full fledge geisha/geiko, they will earn their full wages but will have to buy their own clothes, equipment, training, etc.).
She may also be sending money back to her grandma or her grandmother and father made a condition that a certain percentage of her wages has to go into a savings account for when she gets older or something. When I first started working as a teenage, my dad made me do the same thing.