If she's into plants and stuff, maybe grow her a little flower in a small plant pot. If she is quite glamorous and likes her jewellery, you could buy her a nice lipgloss, something designer to make her feel special. If you are staying with her for the week or something you could make her breakfast in bed and then make her her favourite meal for dinner. And obviously make her a card. You could even write a little poem inside about how much you love her (: She will like anything you make, even if its bad! It's the thought that counts. Hope this helped.