Not mine, the GF's.
Essentially, she's absolutely horrid. The daughter, not the GF. 13 years old, self-centred, selfish, ungrateful, unhelpful, rude, foul-mouthed, arrogant, argumentative, antagonistic, demanding and violent. In and out of trouble at school, too. Usually for back-chatting teachers or fighting.
Apparently she was as good as gold until the hormones kicked-in.
I have no experience of this, I have nothing to bring to the discussion and obviously have no jurisdiction... But the GF is at the end of her tether. I think we are just after some reassurance that this really is "just a phase" and that she's "at a difficult age". Is there an end in sight?
Is she just a textbook teenage daughter who's not had a useful father-figure around for most of her life?
Tell me she'll grow out of it soon. Before she and I have a major falling-out.