A "tricky" one indeed .. I wouldn't stake my reputation (such as it is ..
) on saying whether or not she's TG ..
But if she is a Natal girl & merely using Transgenderism to promote her music & career .. she's not doing the TG community a lot of favours ..
If on the other hand, she is genuine TG .. then good luck to her & she deserves to succeed ..
The "18 years old" Rule also applies in UK .. though I believe that under European Law, that may be waived with parental consent .. and if surgery is considered to be in the best interests of the patient ..