I need to know if I and my wife can go for visa stamping from Canada while her I-539 approval is still pending and my I-797 is approved. Please guide me to the right forum. Thank you.
Yes, i dont see any issue in going for stamping as she is in legal status currently based on pending petition and can use your H1 petition for stamping(just like how she did first time). But once she applies for visa, she should be waiting in Canada till approval before she attempts to reenter. Usually a week time(or more depends on the case).
Make sure she carries the original receipt if asked at consulate/border on what was her legal status proof after I94 expiry.
One time they did ask us and unfortunately we did not have it (even though it was the last to last entry and we received new I94 during the previous entry hence did not bother to take it) and got troubled to go inside with warning saying why we did not carry it hence cbp can question the status in that period.