Wow this is a thought provoking thread!
I personally have never had this dilemma as i've never had a young girl ask me to treat her so i can't answer through work experience only personal experience.
I myself was an early developer and i used to hate PE to the point of making myself sick to avoid it. I begged my mum to let me wax and she said i was too young (also about 9/10) So i did what most children would do i took my dads razor to diy treat myself and ended up covered in cuts and blood everywhere which my mum was left trying to heal.
I also think it's time for people to open their eyes as children are developing so much faster and getting involved with boys earlier. I myself first had sex at 13!!! I know this is disgusting but i don't regret it, i felt ready, i enjoyed being with my 'boyfriend' we played safe etc etc but yes i know that the very thought of a 13yr old being sexually active makes most people sick.
If 'children' are so unhappy with the hair on their bodies maybe through medical reasons, maybe through early development i think we need to think hard and stop seeing them as babies but more as young impressionable people who need help to love their body so they don't abuse it! If a wax strip makes them more confident and less likely to do something silly for false confidence then i'm all for it!
Okay i've laid my heart on the line for this post and it is just my personal opinion so please don't shoot me down for it. I don't mean to offend.. only enlighten.
xxx