Does it make sense that Abigail. . .

. . . more or less turned good at the end and allowed Joey to walk free? Is this character growth credible?

Earlier in the film, even after Joey had been kind to her, she seemed to have no interest in sparing Joey. After all, she's a fucking vampire who had killed so many people that there was a pool full of bodies in the basement, and clearly killing people is just what she does.

For her to suddenly change and show some humanity made me raise and eyebrow and wonder if that had been earned. Or to put it in pro wrestling terms, the face turn felt a little jarring to me.