Currently Being ModeratedMay 1, 2013 4:51 PM (in response to freddiecox)
Try going into your iPad settings for Messaging, tap on "Send & Receive" and look at the entries for "You can be reached by iMessage at:" If your phone number is still designated as a valid address to send an iMessage to, then your wife's texts will be routed to the iPad. For your iPad, you should just be using an e-mail address for iMessage, so uncheck or remove any reference to your phone number.
Then, have your wife go to her Contacts entry for you and tap "Send Message" to initiate a new message thread. She might see various choices besides your phone number, so have her select your phone number and send a text to that. That should do it, but if you have past messages between each other then those might be based on your e-mail, which means it will appear she's sending a "text" to you but it will go out as iMessage because of the dialog history.