I want to call mother and brother for helping me during delivery. Have somebody Idea, or gone through this process, about what documents I need to prepare. I am in F2 status.

Call brother for delivery...

what r u thinking?? Guys interviewing in US Embassy  r nuts??

For Mother... just send the enough bank account and any incomes source or any studentships document and letter stating that u will sponsor her.. during her stay over here...

Best of luck..

my mother does not speak english well, he will help her to reach usa

yeah dd_sh is right. calling your brother for your pregnancy help will put the whole idea into suspicion. There is a chance that your mother will not even get the visa, if they doubt about it.  Unless, your brother is able to show that he is well set up there in nepal and has huge income and a huge bank account,  they will surely reject him. there is no doubt about it. you can try your sister, but not your brother. dont try it. bad idea.