Modern readers are judging this by modern standards and saying Kelly should have kicked Kirk to the kerb sooner and where's her girl power! As someone who actually grew up in an abusive household, I can tell you that's not how these things work. In fact, it's pretty impressive that Kelly blew him off when she did, and that her mother left her abusive father before the violence could extend to herself or her daughter, rather than him just smashing up their home. In reality, ESPECIALLY in the 80s, that would have gone on way longer, and he definitely would have started beating up his wife, if not his daughter.
It's important to remember this stuff was only just starting to be talked about, in those days. Even as I write this in 2022, women still end up in abusive relationships and still keep it secret and allow it to continue, partly out of shame (mentioned in this book) but also because as Kelly says about her father, 'I love him.' But as Tina Turner said, 'What's love got to do with it?'
The drama with Kirk is this book's simplified way of showing that daughters in such families often repeat the mistakes of the past and end up with guys just like their fathers. They don't usually wake up to it as quickly as she did, but in this case, I accept the Sweet Valley Instantaneous Epiphany because they had to get across the point that this stuff is not clear-cut but you DO have the power to set your boundaries and walk away.
Could the book have been a little more brutal and detailed for added realism? Sure. But then, it had reading age parameters to stick to. For what it is, I think it was a bold and important move back in its day. Looking back, I wish I'd read it as a child. Maybe I would have spoken up sooner about what was happening at home. I hope it inspired other girls to speak out and get the help they needed.