F2 stamping for Child when parents are in USA

Hello All,

Need urgent help, my family went to India on an emergency trip. My wife has a valid f1 visa and my elder daughter age 10 need f2 visa. People at the consulate did not accept her passport under IW (interview waiver )saying both parents must have a valid visa, now we are no option but to find a regular interview slot for my child and unable to secure one for the past 2 months. I am in the US on H1b (Second Extention) so my visa expired but has a valid petition.

My wife decided to come back to start her classes, vaccination pending for other US kids and school. So my 10 years old girl will be separated and will be with grandparents for some time.

Q1.Can someone guide me through the process for a Child going for a Visa interview alone? (accompanied by a relatives who can speak English)

Q2. A child going for an interview with a grandparent (who doesn’t speak English)?

Q3. Does she need to carry any separate letters? Any letter or document to show the relationship as a legal guardian?