Visitor's Visa for Minor Children

[immihelp]

Hi,
I would like to sponsor for visitor’s visa for my nieces(brother’s kids) who are aged 13 years. How do I fill out I134 forms? Should I fill out 1 form for each niece? Should I sponsor for the entire family? If I sponsor for my nieces only, will they be allowed to go for visa interview by themselves? Or, do they need an adult. My sister who has 10 year multiple entry visa will accompany them to the US. Can you please guide me?

Thanks.

[immihelp]

1. One I-134 for each person.

2. Yes, they can go for interview on their own.

[immihelp]

Is one set of supporting documents enough for both of them?

[immihelp]

Yes, if they are going for the interview at the same time.