Do you mean:
1. You firt made an appointment with the officer to talk about your mom's situation, and then
2. Your mon scheduled an REGULAR interview via phone, and got her visa?
As I understand you mom did not schedule an special interview with the officer. Is that correct?
Also,
How did you make sure the officer interviewing your mom would know the information you provided prior to the interview? What if you talked to one person and your mom talked another? Do they put the information in the system so everyone will know?
I really appreciate your help. Glad to talk to someone with such experience.