Jay Peak comes to mind. If not, she'll get the wrong impression and every time you take her skiing, her priorities will be in the wrong place. Total emersion.
The total immersion thing might work if you are really careful to heed all the other good advice re: getting her a good lesson, keeping her warm, doing the cooking and planning and so on, etc. You have to make it hard for her to have a bad time. Killington would be a good choice if your girl is really into Jägerbombs, but I have no experience with that kind of chick. I think Lake Placid is a great choice, but were it me in the East I might consider someplace south facing and also around a nice town, say Bromley ferinstance.
I've done this deal twice. One time was a miserable failure. The next I got smart and followed most of the advice in this thread and did it at PCMR, which is not at all total immersion but worked well nonetheless. That one is still skiing, presumably with some other dude.