Getting married, special circumstances..

[SgtSarros]

My fiancee origionally came to the usa under 21, on her dads work visa.

The issue is, that they delayed the filing of the green card, and she turned 21 before the process was completed.

The question is, how long can she stay in the usa for us to get married before she must return to canada?

And if she has to return to canada, how hard would it be for her to come back?