That's bad for business bro.
Make sure continuity is turned off, calls on other devices is turned off and make sure you dont use the same icloud account.
settings/messages/send & Receive.
Make sure just your number on your phone and her number on her phone is selected.
Have you or your wife swapped SIM cards (meaning you put your SIM in her phone to use for a while etc)? Do you share the same iTunes account? If the answer is "yes" to one or both of the questions, that is the source of your problem. Check her phone under Messages > Send and Receive, and see if your email and or phone number is showing under the "can be reached by iMessage at" section.