Milord
i admit, it's a very difficult topic. of course, someone who has been convinced by their parents is not someone who is 100% convinced of the belt, like @Ines for example. there are also some cases here where girls wear the belt because they get something else in return. in general, however, i don't see any big problems as long as wearing the belt has advantages and not wearing it has no disadvantages. i don't really want to judge whether someone can make the decision, because i don't know them personally.
When in doubt, I always have to assume that this decision can be made by the girl and that she has the necessary mental maturity for it, otherwise further discussions would make no sense. At least that's what I believe as long as I'm convinced otherwise.
Legally, you can use the age of consent as a guide, in Germany there is a strict age of consent at 14 and under special conditions at 16 and I always say that if someone is legally allowed to have sex, they can also have the right to give up this freedom, but I am generally the same Opinion to always look at the individual case because the state usually doesn't have absolute wisdom, especially when it comes to such a sensitive topic