A friend from overseas is visiting me in Boston, what should I take her to do?

My friend is a 25 year old girl from Singapore, and I'm 20 year old girl from Boston. She's staying with my family for a week or so this coming January, and I'm just not entirely sure what kinds of things to show her. Singapore is pretty similar to America, so there's really nothing she hasn't already done. The only thing I can think of is sledding/skiing/ice skating, since she's never seen snow before. But that can only take up a day, maybe two if I'm lucky. Is there anyone from Boston that can think of anything exciting to show her?