It depends on what country she is from - she might not have been treated in some countries.
Has she tested positive recently? Is she being treated now? If she has no documented treatment, she needs to be treated with bicillin. If her doctor isn't treating this, she needs to find another doctor.
If you've had sex, its not that likely you'd have it, but you should test to find out for sure.
Aj
I find it hard to believe that it was never treated because I am sure she is at least 14 and to have it this long without major problems would be rare if not impossible.
I suggest she see her Dr for a blood test.