We just received our GC, our daughter is unmarried, over 21 and in the US on F1 International student visa working on OPT. She is eligible to apply for STEM extension in December which will give her a total of 3 years on OPT. We would like to sponsor her for a family based GC, is the timeline for sponsoring a child who is already in the US the same (6 years or so)? If we begin the process now will she still be able to extend OPT to STEM OPT in the fall? She is a Canadian citizen.