My only concern would be that the rest of the class - getting wind of this girl getting extra help - might kick up a fuss. That is what I would have been annoyed about when I did my degree. Fairly, if you offer this help to one student, you should send out an email to all in the class. Its really difficult, I find that some students are just more persistent and get more help than others which is a bit unfair, even when they were probably fine without it.