Hello Ginny,
it's your right to be a supporter if the refugee wants you to be one. The BAMF may not suspend you from the interview (see. § 25 Abs. 6 AsylG).
I added two PDFs, **** for the keyword 'Beistand' (that's what you are).
You can find a brief information here: ****://bit.ly/1UoEqhx
Good luck, Jan