...who's got one?

Mehby's already farming Nether Wart outside his house, so either he built one or there's a communal one, and someone's already found a fortress (or else no Wart).

But the apparently-explored area of Nether is north west of spawn, and I can't see any likely places.

under the village is a nether portal the nether side exit is rather precarious atm needs making safe. I'll try create an obvious path to the nether portal later

EDIT

path made via tunnel under the melon farm most direct route