Bikram,

Becareful. I have heard a lot of cases regarding white girls promising for GC help by legally miarrying, but then after a while abandoning nepalese boys. Your white girl might be exceptional but i have doubts too, since even if it is getting GC by marrying US citizen it takes quite some time, and the authority will dig roots to make sure your marrige is not fake. See the movie GREEN CARD. Hope this helps