You should reciprocate in kind. At least get her a card and, surely, if you have any particular talents or crafts then you should make her something. But there is a difference between one week and three months so you should evaluate how "good" the friendship is and perhaps kick it up a notch, so to speak. While I did say reciprocate in kind, you should also remember that gift-giving isn't tit-for-tat so you can get her something nicer. However, nice doesn't necessarily mean expensive. You can think of something creative. If you two are in college then there are plenty of gadgets and bric-a-brac available for dorm rooms and/or studying which would not be costly but would be useful. Really, you just need to evaluate the friendship and the person. If she is the kind of person to give you a hand-made card then she probably isn't the kind of person to get hung-up on the gift you give her; rather she will probably appreciate the gesture more. So, to conclude, don't sweat it too much and think of it as more of an intuitive task rather than a rigorous and demanding one.