Here it\'s...
Hi,
If you have filed her application PROPERLY with ALL the REQUIRED Documents, Fees and other needed stuff and her application has been MAILED out and You have a PROOF OF Mailing and Delivery(Delivery Confirmation) such as Receipt of mail carrier etc. and has been received by respective Service Center BEFORE Your\'s has been Approved, then you are fine. Even if yours is approved before her\'s(of course, each application takes its own processing time).
Disclaimer: This is NOT a Legal advice. I\'m not responsible for anyone for any effects of following this info. Do at your own risks. Consult a Qualified Immigration Attorney.
PS: You should call the IIO of resp. Service Center to Update her case with your information ONCE you receive the \'I-485 Notice\' of your wife to JUST let them know that her\'s is a \'Derivatice Dependant Application\' and has to be "LINKED" to your case and so that both can be approved together. And confirm this with the IIO.
Hope this helps.
Good Luck and Best Wishes!
Have a good day.
Regards
Princess