1. Rebecca Minkoff Best Friends iPhone Case, naturally.
2. Butter London Holiday Trio because if she's anything like Sally, she's obsessed with nail polish.
3. ..and she'll need a place to store it on the go! (Tory Burch Cosmetic Case)
4. Jennifer Zeuner Love Necklace. A constant reminder of how much you love her!
5. Design Darling Monogrammed Notecards. Handwritten notes to each other beat texts any day.
6. Equipment Pajama Set. If she hasn't splurged on a pair for herself, splurge for her.
7. UGG slippers. No one can resist the coziness. No one.
8. Kate Spade Agenda because if she's anything like Jilly, she will take it everywhere.
9. Target Baroque Picture Frame, filled with a picture of the two of you when you were little.
10. Philosophy Bubble Bath in her favorite scent.
Do you have a sister to shop for?! Anything you'd add to the list?