Joh I assume that Turkish girls in Germany wear their headscarfs with consent. The Turkish community in Germany respects German law.
In Turkey however, parents decide about virginity tests and headscarfs for their daughters from the age of 14 on till the 18th birthday. The legal position there is, that minors do not have the mental maturity for sexual decisions.
Chastity belts are not so common in Turkey, but hymen tests and headscarfs are widely used.
I don't think that a girl will be blamed there when flashing her chastity belt.