Pain in lower leg

[Cell block H fan]

My 13 yr old daughter has had an ache in her shin area of one leg for nearly 2 weeks now. It eases off when she is at home, but when she comes out of school she is moaning & groaning. I assume because she has been walking on it in the day?
I am starting to panick a bit, but obviously not telling her that.
Have made an appointment at the docs monday after school.
She hates doctors & dentists though, so I am not going to say until monday. But I want to see how it goes over the weekend.
Should I be worried? I dont think it sounds muscular. Almost like shin splints but in one leg!

[Cell block H fan]

I signed her off p.e this week as well, to see if not exercising it too much helps.
It seemed to start after a game of tag rugby in p.e the monday before last. But she doesn't remember hitting it. So not sure if it's to do with that.