Asked to return for another interview

[designerqor]

My sister and her husband went for their AOS interview this week. The officer said they did not have enough documents showing that they lived together. He then told them they needed to bring certain documents (I am not sure what) and they would be given another date to return.
My question is does anyone know how long it takes to get this return date? Do they go to the bottom of the list? Do they mail you another date or do you just look online?
Thanks any help is greatly appreciated.

 

[Jackolantern]

Is this a marriage-based green card case? If yes, it seems they will get the "Stokes interview", which is a really tough second interview given when they aren't satisfied with the first. Go to the Family Based Green Card section to search and ask questions about it.