Well, it depends on the budget but since you have not specified one, I take it to mean you're thinking big. You would know better what your sister likes, whether she's into clothes, shoes, jewelery and stuff or not. I think at her age she must be very conscious about her health. Even if she isn't she would be encouraged to exercise if you present her with something that would facilitate exercising at home. If she doesn't have exercise equipment at home you could get her a treadmill or a stationary bike, which would be useful since she's at an age where exercising regularly can help keep her in good health. You could also get one of those shopping coupons from her favorite outlet, so that she can get stuff of her own choice, this way you wouldn't be risking getting her something that she may not really like. You could also sponsor a getaway trip to a holiday spot, it doesn't have to be something as grand (and expensive)as a trip to the Caribbean islands, but a trip to any picturesque or fun place which you can sponsor by simply paying for her hotel stay there would be just as good. You could also pay for a makeover for her at the best salon in town, I bet she'd love it since every woman wants to look her best and this maybe something she may have not paid attention to and I'm sure she'd love it and appreciate it too. So, I guess since she's your sister and you know her better you'd be able to pick the best suggestion out of all these and I hope you'll find them useful. Good luck!
