Wool mittens, handmade in Brooklyn, $45. (There are sold out, but here's a similar pair).
Porcelain bag vase, $35. (Flower delivery optional.)
A candle that smells like the seashore, $30. (You could wrap it in this cute tote.)
Anchor notecards, $28 for ten.
Peanut-butter-and-jelly rugelach cookies, made by the two adorable sisters above, $20 (about 24 pieces).
Kneepad tights to show off her cute quirkiness, $35.
Lavender sachets (inspired by vintage seed packs) for her dresser drawers, $19.
A silk friendship bracelet, because you're not just sisters, $38.
P.S. More gifts for sisters...