Ginny never really grew out of the crush she had for Harry, and she never had a serious relationship before Harry in Canon, from what I've understood. But it might be that I'm misremembering things, I am a serious Harmony ship (Harry and Hermione) fan, and dislike Ginny's character in general. The fact she doesn't even volunteer to help Harry on the Hunt is major points against her, sure she wasn't aware of the specifics, but the fact he was going to be not attending Hogwarts for his 7th year and doing something else to stop Voldemort was known. Compared to Hermione who freaking mind wiped her parents to get them to move to Australia then goes on to join Harry on the Hunt? Yeah Ginny has never deserved Harry.
But yes I see Ginny causing issues, really if Taylor and her can be anything more than frigidly cordial to one another at best I'll be surprised. I just don't see that in their characters. Molly will also be a problem. It's quite understandable why Fics often just choose to bash those 3 Weasleys as characters, it's just easier to get them out of the way. Taylor is for sure not going to let Harry dawdle around in Divination with Ron, and instead will force Harry to try to gain more knowledge in other areas like Runes or Potions to improve their odds at beating Voldemort. If she chooses to explain why, and all indications are that she would do so in this Fic given she was honest about being a villain, he's even likely to agree with her.