self sponsorship

[SUKRINA]

Hi,
My sister is planning on coming here to US to give her USMLE step2 Clinical exam in October. Her visa interview is on Sep 21st in Delhi. She is self-employed , married and has two kids who are 14 and 10 yo. She will be self-sponsoring for a visitor's visa and state that she is coming here to take the USMLE Step 2 exam and to have a reunion with her brother and sister. I am her younger sister, a naturalized US citizen, our younger brother lives here too, he is on H1B. My questions are --
1. Is self sponsorship is the best way to go for her? She was told by her collegues and friends that it is the best way to go, is that so?
2. Is it OK that she is also mentioning about visiting me and our brother ?
3. In her visa appt. she gave me as the POC in the US. Do I need to send any documents or letter of invite to her?
4. How much of bank balance do they expect to see for self-sponsorship?
5. When you state that your are self-sponsoring your trip, does that mean you are responsible for all the expenses you incur while you are here, like travel arrangements and all boarding and lodging and visitors' insurance?

I would really appreciate if you can clarify these questions for me. Thanks for your help.

[immihelp]

1. yes.
2. yes.
3. no.
4. Enough to take care of all the expenses for the trip.
5. yes.

[taco]

1. Yes, self-funding the trip is the right way to go.
2. Her answer should be a straight
step2 cskills exam, because that is the primary purpose. Let her not
bring family union into this.
Immediate relatives of US citizens may have difficulty getting
a visitor visa because they are eligible for an immigrant visa(strange, yes) but since her purpose is to take the test, she may succeed.
3. You could send her a letter of invitation (mention the test)since she has mentioned you as the POC. Anyway, both of you in US are required to be mentioned on the app form.
4.No pre-set limit. Many times, they only ask you about your income or look at your tax returns to get an idea if you can afford the trip.
5.Yes, but the consular only needs a general idea from your income and
savings.

[SUKRINA]

Letter of invitation?

Immihelp and taco, Thanks so much for your replies and advice. It is really helpful to bounce off ideas and questions on this forum.

BTW, what kind of letter of invitation? I am not sure what I have to write. Please help me, give me some pointers as to what I should write on this. Is this something I address to her or the consular? Does she have to file this with her DS-156 or show when asked at the interview? Thanks again for your help. It is very much appreaciated.