We're going to start this post from the premise that middle school girls, even the good ones (and they're all good ones) are little shits who believe that the world was invented specifically to honor their wonderfulness, and that good things, like figure skating lessons, are actually the universe trying to keep them from enjoying themselves.
That said, high level figure skating is a lot to ask of a 12 year old.
Under the eagle eye of the gossip brigade in the stands, your 12 year old (or 9 year old, or 16 year old) is, mostly, working. She knows she'll catch hell on the ride home if she spends too much time at the boards when you're watching.
A lot of parents feel like they have to be in the stands every minute, and fear that if they aren't there, the kids will just fool around. And I'll say this again-- if your child legitimately wants to achieve her skating goal, be it making it to Nationals, getting a solo in the ice show, or passing tests, fooling around will be a self-limiting strategy.
The thing to watch for is not whether she's using her practice time effectively, or paying attention in lessons, or even if she's falling short of the goals. The thing to watch for is how she reacts when she falls short of the goal, especially if the reason is that she hasn't been working hard. If your skater goofs off and then blames everyone around her when she fails, she's not all that committed to skating, and may in fact be taking it a little bit for granted. If she goofs off and then doesn't care when she fails, you may want to rethink how much you're spending on skating.
If she works hard and fails, even if she doesn't take it well, you can be pretty sure she's not taking it for granted.
In a way, we all take it for granted. Kids, for one, never understand how lucky they are. I hated school until I had to work full time and realized how unbelievably awesome it is be able to spend all day learning and hanging out with peers. I have to remind myself regularly what an incredible gift it is to have the amazing job of teaching figure skating.
I think you have to remember that if you've chosen skating for your child (with the child's help of course), it's not really any different than anything that you feel your child is taking for granted-- the pile of presents at the winter holidays, regular meals, indulgent parents, enough money for treats.
Don't you take it for granted either. Your kid can land an axel, or will. Do you know how hard that is?