I didn't know Mary was 13, only that she was considerably youngerthan Joseph. We don't know her precise age but seems she could have been thirteen when she was betrothed to Joseph. Her age is asked frequently, I googled & came up with much info. Some 'religious', naturally enough, but some of it also quite informaative regarding the customs of that period. This one for example:-
http://www.truthortradition.com/articles/mary-a-teenage-bride-and-motherChildren used to be married off at very young ages in this country at one time, especially those from 'noble houses'. Could be widowed before reaching puberty!
Until recent years the age of consent in Ireland was 14& is 14 or 15 for some European countries. It's been seventeen for quite a while now in Ireland, older than most other places.
Returning to the subject of civil partnerships for heterosexual couples, i don't see the point but I do get what Rhiannon says about solemn, public vows. In which case why not live together & make private commitment? Plenty do. If a couple own a house jointly in both names & one dies, the other gets their half. Reading up on my own pensions, one of which I'' get at 60, the other 65, I can name anyone to receive it if I die, doesn't have to be a husband. As for other property, like car & jewellery, I can make a will.