The sad fact is that bullies do not seem to change, so the point will arrive where the bully or the victim has to move on. Fairness and what little employer advice that exists says move the bully, not the victim. This seldom happens in reality, as bosses are like water and take the easiest route.
If you have a union helping you, gf can begin to get the right advice for her asap but in this situation the reality is that she will probably want to work somewhere else. The important thing is to take control of this decision and make it in your own time - ie going, but not being pushed. Be wary of litigation firms who promise constructive dismissal payouts as this hardly ever happens.
Be realistic, get what is best for gf out of a lousy situation, and make positive plans that please her for moving on and being happier somewhere else.
Oh, and she is not weak - not a wimp- - the other verbal abuse is 'clearly not a tram player' - she has every right not to be bullied, but the world is not a fair place.
The guy who set up this website died not long ago, doubtless aided by the stress he experienced from bullying:
http://www.workplacebullying.co.uk/aethesis.ht ml