"Hun bliver fulgt hjem af drengen."

This reminds me about one joke we used to make to one of my class mates: - [Name] managed to save a girl today. -How comes? -He stopped chasing her. :))

Actually, it means he accompanied her! But that doesn't use a passive in English. There should have been enough context to explain it!

So how do you say "She is being followed home (by a stalker)""

"She was accompanied home by the boy" is a better translation

Nasty boy must be stalking her