@cinnamoncookie I was unsure about this too, so I came to a conclusion that they always cared about her, but since she was behaving horribly they stopped showing it. I mean, she was really edgy, so their care might have died out. And when she started to behave more like a normal person, their care came back to life again. They still are really rough and it is visible that they lack "a female touch" if you know what I mean. But still, if they really hated her, they would have disposed of her long ago (I know their family is known and it might not be so easy to do it but I'm sure there was a way or two to achieve that if they really wanted).
It still does not excuse their mean behaviour towards her, but it is really hard to judge since it was originally a game with a lot of bad, brutal endings. We know how cruel they can be, but not everything bad in the game will happen to current penelope, since she is trying her best. I still don't like their behaviour, especially fathers', he is a grown ass adult, I though he would be more curious or understanding towards Penelope, but well...