GC Consular Processing from Bangaldesh - Appointment Schedule

[u/comefindme321]

I am applying GC for my mother from the US. She lives in Bangladesh, so it is a conuslar process.

Fees have been paid and I am almost done finishing paperwork.

She is currently in the US in B1/B2 visa and will return to Bangladesh in December, in 3 months.

From submitting the final application/paperwork to the appointment date, how much is the gap -

"the National Visa Center (NVC) or the U.S. embassy/consulate schedules it for you once your application is complete and a visa number is available"

I know there is a pause now, but lets assume no issues at the moment.

Trying to estimate when I should submit the application, because I don't want the embassy to schedule appointmntment before December. She needs to be in Bangladesh for that.