I have two BELL kids helmet.
They are $15 each. The boys one fits a head size 52-56cm. It is in great condition and has the extra reflectors on the back of the helmet.
The red one says fits 5 and older.
I would say it would fit a 8-12 year old girl.
It has a couple cracks on the top from it getting dropped on the cement.
Cash or Venmo.