You'll have to give her more gifts, stuff that she actually likes. Giving a gift will grant a star but the type of gift is important too as that modifies a hidden number for each character and based on what you said, the number isn't high enough yet.
Oh, okay, I see what the problem is. It's a trigger bug. I'm going to have to release a hotfix for it. The BJ scene has caused issues with chapter 3 as that content was copy pasted over from a newer version and unfortunately I didn't properly account for the old trigger. I'll have to release a new update.
Check in within an hour for a 0.04B_c, you'll have to redownload it but you'll be able to use your old save file and continue where you left off. So sorry about that and thank you for letting me know.