Can't give you statistics, but it's a lot of fun and an absolutely great way to introduce yougsters to flying. Don't know about the UK or OZ, but here in Texas (where have I heard THAT before

)...Here in texas you can solo at 14. How many of their chums at school could have anything to match that?
BTW, I had my nephew out this summer as he turned 14 last Dec and I got him to where I thought he was ready to go. Had to put him through a stage check and the local guy said he was pretty much ready but perhaps a few more times around the pattern and he'd sign him off. We ran out of time unfortunately, but I spoke with the boy and it was good to see that he wasn't interested on the solo so much as he was on being safe and learning thouroughly etc. Of course, he is of above average intelligence
If you don't hate your ex, you could try to arrange a day there for every one and let her see for herself what goes on as knowledge conquers fear right? That way, everyone gets involved and takes it nice and slowly.
Gool Luck
Onan CFIG
BTW, the stage check guy was a nice bloke, but I was pretty much up to the point where I had to take a good book with me as even a 14 year old can do very uneventful patterns.