I don't think there is a strong risk that she will be denied entry on the F-1. The main way that USCIS knows someone is married to a US citizen is if there is a I-130 petition pending, and there won't be one for her. I am trying to imagine a conversation that border patrol would have with her that would reveal the marriage, and I can't really think of one. F-1s travel on vacation all the time and return, and as long everything is in order for her F-1 visa I wouldn't have a strong expectation that there will be a problem. Of course, she has to be honest if CBP asks if she is married. In addition, she definitely needs to be in-status on her F-1 when she returns. Hopefully she is still in school and can explain to the CBP that she went on vacation but is coming back to go back to school. Still, you have identified a risk, and only you can say if you're willing to accept it. As far the options you were describing go:
Option C definitely won't work. You can't expedite a CR-1 or K-3. It can take 5 months to more than a year.
Option B could work if you work quickly. You'll need to gather everything you need for an AOS application and get the marriage certificate soon, so you have time to submit the application for adjustment of status and advance parole. I am not aware of any companies that expedite advance parole, but you can ask USCIS to expedite AP if you have proof of imminent travel plans. I would imagine that most people spend several weeks to several months putting together their AOS papers, so it just depends on how quickly you can work and what you might need that will hold you up (medical examination and vaccinations come to mind, but you need a lot of other things too).
Option A could also work, but again I am not sure there is much difference between getting married before or after the honeymoon. It makes sense to avoid adjusting status soon after entry whether or not she is married when you go on your honeymoon.
Thanks for the speedy advice (to you and all others as well). A few extra tidbits in response to this:
1. She is in-status on her F1 for three more years.
2. If we do go with A, how much risk is there down the road at her AOS interview? If we delay the certificate until some number of days after the honeymoon, would it still be a problem that we met, got engaged and conducted a ceremony prior to her re-entry? It would be great if someone could give me a sense of how much risk we would be introducing into her life by trying A.
3. Several people asked what I was thinking about expedition. What I had in mind was something like passport expedition services -- I know there are several companies out there offering high-speed passport processing for a price. But from what everyone is saying, it sounds like there is no such option here, regardless of which immigration paperwork is necessary.
4. It is sounding like the only real option is to postpone the honeymoon and take the financial hit. Do others agree with this?
EDIT: I see that while I wrote this, several people have advised against option A. I do not mean to violate TOS by pushing on option A above, so please consider my request null and void in that case.
Edited by kenfeyl, 22 April 2012 - 10:56 PM.