Dodgy as fuck.
Only signed up yesterday and is accessing from Nigeria
.
Good luck to her if she's in Nigeria at the moment - one of those rare occasions where one can truthfully say you'd much rather be in Swindon !
The alternative explanation could be that she's using a VPN, which can make her appear to be accessing the site from anywhere in the world.
But you're right, I'd go with her actually signing up and living in Nigeria as the most likely explanation.