I'm a mom and I've just found this forum. My daughter is from the West Coast, so I know what she should wear for our area, however she will be interviewing at Tufts, as a late interviewer, and I tend to think that the East Coast is more formal. Do you think my daughter should wear a skirted suit?

I don't know that much about Boston, but I'm leaning towards buying her a regular women's suit that has a skirt. However, it will be cold.

Any info would be helpful.

I'm a guy but I would go with the pants suit thing. I think it would be a little too cold in Boston right now for a skirt.

Maybe you should let your daughter decide what she wants to wear and let her buy her own suit.
But to answer your question, a suit is a must. Pants or a skirt are both fine, she should wear whatever she is more comfortable in.