US visitor visa from Botswana US Embassy

[immihelp]

Hi-
My mother is currently in Botswana with my brother's family for few months. We are from Tamilnadu. Indian Citizen.
Since my brother is working in Botswana with residential-status, my mother has also got residential-status in Botswana recently. My father is no-more.

Am working in USA with H-1B status now, and I would like to invite my mother to USA to be with me for 6 months from Botswana.

Question:
- Can my mother appear in US embassy in Botswana to get US visitor visa? Is it a violation legally?
- What are the specifics need to be taken care of?
- Any special documents needed for her USA vistor visa process?
-

All inputs can be greatly appreciated.

[immihelp]

1. That's fine. NO problem.
2 & 3. Read https://www.immihelp.com/usa-visas/visitor