Applying visitor visa for my sister

[nimika]

Hello,

I am currently USA citizen ( came on H1b and in usa for 15 yrs) and am applying for my sister and her fmly visitor visa for first time what kind of questions are expected anyone applied for the same ? can you share your experience

I have field Immigration petition for them will that impact in getting visitor visa . They don't plan to migrate but i just applied as it takes 15-20 yrs and we don't know what situation is going to be there after 15 yrs

can someone share the experience if applied for the same

Thanks
Sagar