Timeline
Labor Certification Filed: 04/14/2020
Labor Certification Approved: 09/17/2020
I-140 Filed (Premium Processing): 10/19/2020
I-140 Approved: 10/27/2020
DS-260 Filed: 11/24/2020
Interview at US Consulate United Kingdom: 02/04/2022
EW3 / EW4 Immigrant Visas Approved: 04/19/2022
You can do this process outside of the country you were born in! While this can make the situation more complicated and you must have a reason to process in another country, it is possible to do the EB-3 Unskilled Visa as a Third Country National.
Congrats to this family for getting their Green Cards in just 24 months despite starting right at the beginning of the COVID-19 pandemic.