Hair loss/thinning in children

Hairdresser has been today and I asked her if she thought pips hair was thinning at the back. She had a look and said yes she's definitely got hair loss going on on one side of her head. She said it doesn't look broken or snapped of but like it has fallen out in patches. Pips has really thick hair so it's not too obvious, but I'm not sure why, any one have any experience or suggestions (hairdresser says her scalp looks fine and no sign of ringworm or the like when I checked)

No direct experience but could it be alopecia? or might she be pulling it out?

@sim I've not seen her pulling her hair, not sure if I should take her to GP or just see how it goes

Perhaps keep an eye for a while as hair growth is a cycle. Take a picture now so you can compare later if you do go to the GP?