I haven't seen any Nepali females but there are plenty of Indian females in US army.I am not sure about the age bar but i think if you are in your 20s or 30s you should  be alright.And if you have bachelor's  degree you will get  enlisted as E-4 (SPC), and if you have few college you will be enlisted as E-3(PFC) and you are  just out high school make sure to tell your recruiter that  you can bring some more people in the army and  give some names he  has power to enlist as E-3 , if not you will be enlisted as E-1.So, better try  your best to come as E-3.Here is the link which will tell you how much push ups , sits ups and run time you need to pass your physical test.Make sure you are able to get 60% in each event  before you go to see recruiter, that's all you need.It will make your life lost  easier.
http://usmilitary.about.com/od/army/a/afpt.htm
And  get some job in financial department or computers you know something like paper pusher or if there is nothing available get something related to aircraft mechanic.These jobs are easy, risk free and will give you lots of experience for yr  civilian career.
If you wanna know anything else just let me know here, i will be glad to reply  you.

thankyou very much role model. i have some other doubts too for that i want to talk to u personally so can i have ur email id?? 

yeah sure shoot me an email at role_model1002000@yahoo.com

I thought the MAVNI program was already closed. No?