Can you suggest a birthday gift for a 25 year old girl who is very fashionable and health conscious?

My sister is turning 25. She likes nice clothes, and she has a good job so she can afford them. She lives in NYC and she shops in very nice stores, like on Madison Avenue. Her style is somewhat preppy. She also is very health conscious, tries not to eat meat, eats mostly salad and grains, although she does like tea and coffee. She plays tennis and is learning golf.

In the past, i have given her Starbucks gift cards, soaps from Whole Foods and Trader Joe’s, the Martha Stewart Baking Book and a whole grains cook book. I have also given her money as a gift. I would not try to buy her clothing as she is too fashionable for me to even guess what she would like.

I can spend $100 and max $150. Cash is a last resort, as I would like to give her a present.

Any ideas?