I have heard a case in New Hemshire that the guy did go to the senator and the senator's office made a call to Nepal embassy and they got the visa. But before you do that find out from your wife the reason they are giving her for the rejection of her visa and try to correct them if you can. One thing I found out is that a good amount of money in the bank goes a long way. That way they'll know that you'll be able to support her during her stay here in the US.  Since you are on F1 which means you can only work in campus for 20 hours a week and she won't be able to work under her F2, so having a good about of money here in the bank or if she is able to show them how all your expences are going to be met then I am sure they won't have any problem issuing her a visa.
All the best. It must be really hard living apart like this.