She needs to contact the US consulate closest to where she lives. Normally, they will be able to tell her what she needs to bring and what the procedure is. This information should also be available on consular web site. Most consulates also respond to e-mail enquiries.
I see no reason why not.
In my view, a B-1 would be appropriate because you are not engaging in any employment that would take a job away from a US worker and you are not getting paid for your appearances.
The following FAQ should cover the issues.
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