US Immigration from Ghana

I started the filing process for my mom since 2018 she got approved years ago but went for the interview last month. After the interview she was informed to bring the original copy of my birth certificate and a police report and her passport was taken and not given to her she was informed to submit the documents at the DHL in Accra Ghana which she has submitted. We received an email stating that she has been approved for an ALL IV IR2 visa and was instructed to continue scheduling at a link when we logged in we selected the visa type and the message we received was there was currently no appointment available I am confused I am not sure if my mom has to go for another interview to submit those document or Waite on an email that her visa is ready. Can someone please advise if they have been through this situation before.
thank you

B1/B2 VISA NOW MARRIED TO US CITIZEN, BUT US CITIZEN ONCE MARRIED TO SOMEONE WITH B1/B2 VISA AND GET GC AND BUT DIVORCE 2 YEARS AGO.

NEED THE LISTS OF FORMS NEEDED FOR ADJUSTMENT OF STATUS AND ALSO LISTS OF SUPPORTING DOCUMENTS NEEDED. I'LL APPRECIATE YOUR HONEST REPLY AND SUPPORT IN THIS JOURNEY OF OURS

How long will it take for my siblings to move here from Ghana , west Africa if my mum( green card holder files for them. ) they are adults , unmarried

So given that the USCIS now processes cases electronically and some of us still filing applications non-electronically. Would the USCIS still send the physical file to NVC onwards to the embassies like we know they do sometime past?

Submitted documents in February of last year received Approval April the 4th. How long will it take to notify fiancee in Ghana and what is the next step?