[spoilers] Harry and Ruth

[Nia M]

I think that if she did love George, it was always with reservations of some form. Initially I would have said that was simply that she was adjusting to having lost Harry and having given up everything and gone on the run, and struggling to accept that she would never see him again, then I think she would have just felt guilty at even the thought of another man, because she feels she is betraying Harry in some way (even though he is techincally lost to her).
Since we didn't really find out enough about her and George in the series, I'm going to make a few assumptions.
I reckon that initially hers and George's relationship was purely just friendship, something that she would be evidently lacking in now in exile, and something that she would welcome. She trusts him, and he is kind, but he is still not Harry.
Their mutual friendship and respect does slowly blossom into something more - I would say that perhaps she can be wholly at ease with him (and also with Nico) and it offers her a sense of comfort and security that she has been missing for a while.
I think that she did love George, and she loved who she was able to be when she was with him (ouch, that sounds so clichéd...) but there was always some trepidation about the fact that he did not know the truth of her past. And she couldn't tell him that, because to do so would bring back its ghosts, and she wouldn't be able to go through that again. So it was just buried out of sight, but still there - hence she could not marry George. (Also, in making their relationship official, she'd be completely letting go of Harry, something I don't think she could bring herself to do.)
Then when George is killed, naturally she feels responsible (even if she does also blame Harry) for his death. She feels guilty that she never told him the truth, and guilty that she had moved on, as it were, from Harry (even though her only other real alternative was to sit and mope for the rest of her life, alone) and it is these two conflicting emotions, and the fact that she now feels she is betraying George by still loving Harry (because yes, she really reaally does), that through her feelings for Harry into such turmoil.

Crikey, that was an essay and a half!