Sub 4:50 mile/1600m, or 1500m?
I don't know much about Georgetown running, but they aren't on the same level as Princeton and Stanford academically. I'm not sure why she would want to go there if she could go to the other two.
I've spent some time at Princeton and Stanford. The running at Stanford is a dream. The weather is great almost year-round, tons of trails, great teammates, great school. Princeton has a few running options, but it gets kind of boring and the weather can be miserable at times. Princeton has a bit of a reputation for not developing its runners fully -- they get awesome recruits but don't always do as well as maybe they should.
If you think Palo Alto is boring (I don't, but I haven't lived there, only spent a few afternoons in town), Princeton is worse, there really isn't much there aside from the school; the town itself is quite small and shuts down pretty early in the evening. The student population of Stanford is larger so there's more going on there. On weekends or for special events, Palo Alto is a fairly short cheap train ride from San Francisco, Princeton is a fairly short cheap train ride from NYC, so I think they're comparable in that sense. One difference is that Palo Alto has forests/state parks/open spaces nearby that the word "beautiful" doesn't even begin to describe. Princeton has... rural New Jersey. If she's at all an outdoorsy person, Stanford is the much nicer choice.
I don't think Princeton is a stretch if she's being recruited, recruited runners have much lower academic standards and based on what you've told us she probably fulfills them (is she in the top 1/3 of her graduating class?). *If* the coach wants her, she's probably in. Same for Stanford.
Princeton doesn't offer athletic scholarships, but it does offer generous need-based financial aid packages. If her family doesn't make a lot of money it may even be free. It would be prudent to look into that before making a decision.
There's also a significant cultural difference between east and west coast. People on the east coast can be more... intense(?) -- and it can be tough to adjust to that environment if she's from the west coast.
Princeton also has a higher percentage of recruited athletes and other types of "hooked" students, which annoyed me as a student (I wanted bright classmates).
Overall, I would go to Stanford for cultural reasons, better weather, and coaching, but different people may have different opinions.