I shall clarify.
In TFA and TLJ, Rey focused heavily on her parents, they were the ones who conceived her, birthed her and abandoned her on the hell that is Jakku. She hoped there has to be some reason as to why her parents abandoned her, like being important in a way it would, for example, motivate her parents to abandon her, showing how they loved her. Of course, Rey comes to terms with the truth in TLJ and stops caring about her parents, but just because she stopped caring about them doesn’t indicate as to whether she cares about her grandparents or not.
Rey is absolutely scared of her Palpatine heritage in TRoS, because, due to her lack of self-worth, she fears being rejected by everyone, she fears about what everyone else would think if they find out of her heritage, she fears that no one is going to give her validation if they find out her heritage. This is implied in some later scenes, including her following conversation with Finn (“Rey, I know you…” “People keep telling me they know me. I’m afraid no one does…”).