I am glad that this law has been brought in. There is a lot of confusion over childhood and adulthood and this clarifies it.
Having said that, I am not over-optimistic that it will work in any way against under-age religious marriages in some communities. I know from experience that I could tell girls, until I was blue in the teeth, that their mosque wedding (usually aged about 15) was not legal - and I might as well have breathed against a heavy brass door.
Well, it is as it is. I can't do much more except to say that I once attended a 'wedding' of a pupil's sister and I was horrified about the bride's status as a commodity (she was O.16).