However, this process is usually much shorter comparing to the employment based green card application (usually several months).
After you get married, she can submit 485 immediately. This will allow her to stay in the US legally even if her other status (including F1 and OPT) has expired. So there will be no problem for her.
After you get married, she can submit 485 immediately. This will allow her to stay in the US legally even if her other status (including F1 and OPT) has expired. So there will be no problem for her.