回複：a little complicated question needs answer please

Question 3 first: not many people have the same experience.

Question 1: She will most likely to get B2.

Question 2: Of course they can, but it is up to US consulate to decided if they can be interviewed together.

BTW, hiding you in application is a bad idea, because if the US consulate finds out, none of them would have any chance to get visa, and ever later.