Baldysquirt - your gf's experience is very similar to my friend's experience as a ~23 year old new graduate: thrown into the deep end with an unmanageable caseload, no support, chronic understaffing and completely out of their depth. Anyone that cares about what they do would be driven crazy; anyone that doesn't care about what they do shouldn't be doing social work in the first place.
In line with what was said above, "as having no knowledge of a subject is no bar to expressing an opinion on here, then I'll chip in my tuppenceworth", I'll chip in too, admitting that I have only second-hand knowledge of social services through a) someone who was reported to social services for something more or less similar to the off-night-shift-can-of-beer story above and whose case was dealt with discreetly and appropriately, and b) a whole bunch of people that deal and work with kids in really crappy situations.
My impression of being a social worker is that by nature it is incredibly hard, presents a lot of very difficult dilemmas about risk and conflicting objectives, involves dealing with the victims and perpetrators of unfathomable misery, and is emotionally and intellectually draining - and all of this interspersed with positively impacting someone in a way that can change their life for the better. Moreover, by virtue of the apparent poor management and poor funding of the services as they are now from the top down, most social services departments (to my ignorant eyes) seem to be a complete shitshow of an unpleasant place to work. This is such a difficult and important job that we want the best people available to do it, to reward them properly for it, and to make their working environment and processes as comfortable and conducive to success as possible. And what do they end up with?
I've done some pretty tough/high-pressure work in the past that involved following some pretty nasty and violent people, but I don't think I would last a week as a social worker.