I did some searching on the web and found this. I can file the immigrant petition (I-130) and the waiver at the same time. Once approval of the immigrant petition is obtained, my wife will need to satisfy the two-year Foreign Residency Requirement before she is eligible to apply for an immigrant visa. She may satisfy the Foreign Residency Requirement by either obtaining a waiver or residing in your home country for two (2) years. If the waiver is denied, then she will have to wait for the 2 years to apply for an immigrant visa.

Please let me know if there is anything I miss.
Thanks