Opus Dei

Opus Dei is basically the masons for Catholics only a little more out in the open and easier to join. Although they do have their own set of fairly hardline beliefs, these days they act far more as a networking group than any form of religious sect.

They aren't likely to start demanding money off her or any weird cult shit like that and many Opus Dei members have got pretty nifty jobs as a result of membership. Personally, I think joining any society like the Masons or Opus Dei or St Vincent de Paul is pretty gay, I'd rather make my own way in the world and not owe too many people favours but there's unlikely to be any harm in her joining.

Step back from all the conspiracy theory bullshit and they're little more than a social networking society. I wouldn't worry about it if I were you mate.

Jam it back in, in the dark.