Unfortunately with skeletal remains, often all you can tell from teeth, growth plates, and all the other clues is "fully adult, but younger than when arthritis and wear start to make their mark." But I've always felt like she was probably at the younger end of the age range--no evidence for that, just a gut feeling and probably wrong.
Hopefully we won't have to wait too much longer to find out who she is.
I feel like she is on the younger side as well. Due to the recon and her clothing.