@lajalu_ In my opinion the kids will do just fine overtime.They will most likely make more close friends here in Nepal than in US. Finding job may take a while especially if you plan on staying at big cities as a nurse (connection is KEY). If you haven't already, I suggest you write down all your (family) priorities and compare cons and pros of both US and Nepal and see if you still plan on moving back to Nepal (This is what I did when I moved back Nepal myself and OVERALL I have been significantly happier here in Nepal compared to US).
Remember life in Nepal is going to be really challenging for first 2-3 months so be mentally prepared for that. Also, I would suggest you to move during 1 month or so school break here in Nepal. The 1st month will be really hard on all of you so moving during school break gives you time to visit places and spend ample time together while you are also getting acclimated here. Wish you all the best on whatever you decide.