F1 OPT to H4 EAD

Hi

My wife just started her F1 OPT and we just got to know that she is pregnant. I am currently on H1B and has my I-140 approved. We are thinking about changing her to H4 EAD. Looking at the current processing time for F1 to H4 it can take more than 1 year. If we apply for H4 now can we apply for 2 year F1 OPT extension incase H4 takes longer than 1 year?

Regards
Ajay

You map apply for STEM OPT while her H4 COS is pending. Once the COS from F1 to H4 takes place, she will no longer be able to work on STEM OPT EAD until her H4 EAD is approved.