I began wearing contacts when I was 15.
I was very very very shortsighted - am now almost at the edge of what they can correct :( so to go from very thick heavy lensed specs to contacts was AMAZING!!!
My optician wouldn't start me on them any younger than that as they wanted to wait for my eyes to stabilise first, so this may be an issue for your DD.
I wore hard gas permeable lenses for the first six or seven years. You take them out every night, clean them, store them. They are the 'best' for your eyes in some ways as they actually hold the cornea in shape (I had astigmatism as well as short sightedness) and the GP ones let loads of oxygen in onto your eyeball. HOWEVER, if you are a bit lax at looking after them you can get eye infections fairly easily and if you have a few drinks and fall asleep in them you can end up in big trouble as they can float around and get wedged at the top of your eye, very sore and painful.
They work out cheaper than daily disposables (just) but still need replacing every 12 months - tbh you might find it easier to spread the costs.
I moved to dailies after losing the third lens at a festival in as many months - I was doing a lot of travelling, camping etc and decided that it just wasn't worth the hassle and the expense of having to replace lost lenses.
Since moving to daily lenses I have not had a single sty or infection (used to get a couple every year) and when you are travelling etc it is SO much easier.
I do feel guilty about the waste though - all those plastic pods in landfill!
I would definitely start by taking your daughter to the optician, talking through the expense etc. It is not cheap - I pay about £65 for 3 months supply and you still need glasses for morning / evening etc.
When did she last have her eyes tested? If she is wearing them all day with no headaches / problems it could be that she does need them 'full time' after all. Your prescription can change really quickly when you are still growing so it is worth making sure you are up to date on this.