Don't brag about PHD, i think her parents are doing what they should be doing. What do you think you'll do with you Phd in US ? When will u get ur Green Card ? When can you bring her to United States after you get married. 
She doesn't wanna be left in Kathmandu after you get married. . . Everyone knows how US Embassy is....So i think her parents know the situation very well....
What are you doing your Phd on ? Is it really worth it ? Are you doing it just to maintain your Status ? Then it's not worth it... Guys with just  Bachelor degree in Computer Science (IT) are well settled in US and making 80k-100k already and they've Green Card Citizenship by now.

By the time you complete your degree you'll be old, and depending on the Subject you might struggle making 80k-100k and Green Card is Far away. ..

Don't overestimate yourself saying you're doing your Phd......You're nothing.