QUOTE(warlord @ Nov 2 2007, 05:28 AM)

Why would getting married on a green card be different then if she was a USC? I guess I can't think of anything that would be different unless her finance doesn't have a GC, but if he was in highschool then I assume he was...
The OP said she filed an I-130, and the wait is less if you're a US Citizen. I'd assume the new spouse doesn't have a GC. I'd guess the OP's daughter probably married a sweetheart from her high school in the other country, but there are other possibilities.
Regardless, the other posters are right. It's a hard statuatory requirement to have the green card for five years before attaining citizenship, and no bureaucrat has the authority to waive that requirement, even if the GC was delayed due to a USCIS error. The only choices are to either wait the full five years (you can file the paperwork 90 days before the five years are up, provided all other requirements are met), or to try and fit into one of the categories for which the five year continuous residence requirement doesn't apply. You can scan the M-476 to see what special circumstances can shortcut the five year requirement, but from my memory, military service is about the only one that would seem likely to be possible, and that may not be palatable. Marriage to a US citizen would shortcut it to three years, but that doesn't seem to be a possibility in your daughter's case.
There might be some remote possibility of getting them to retroactively change the effective date of permanent residence, but that REALLY, REALLY doesn't seem likely. Speak to that expensive lawyer, and if there's any chance of trying this strategy, expect it to be expensive.