iPad iMessage help?

Yes you can.

On her iPad go to Settings>Messages>Send and Receive at>You can be reached for iMessage at>Uncheck your phone number. Then tap add another email address for your wife to use for Messages. I'm sure she has her own email address. Then let Apple verify the email address, check that as the email address that she uses for messages.

Take a look at his.

http://macmost.com/setting-up-multiple-ios-devices-for-messages-and-facetime.htm l

Either I missed it the first time around or you edited your post. Doesn't matter... If she wants to link her iPhone number to Messages look at this and read it all the way to the end.

http://support.apple.com/kb/HT5538

Using FaceTime http://support.apple.com/kb/ht4319

Troubleshooting FaceTime http://support.apple.com/kb/TS3367

The Complete Guide to FaceTime + iMessage: Setup, Use, and Troubleshooting

http://tinyurl.com/a7odey8

Troubleshooting FaceTime and iMessage activation

http://support.apple.com/kb/TS4268

Using FaceTime and iMessage behind a firewall

http://support.apple.com/kb/HT4245

iOS: About Messages

http://support.apple.com/kb/HT3529

Set up iMessage

http://www.apple.com/ca/ios/messages/

Troubleshooting Messages

http://support.apple.com/kb/TS2755

Troubleshooting iMessage Issues: Some Useful Tips You Should Try

http://www.igeeksblog.com/troubleshooting-imessage-issues/

Setting Up Multiple iOS Devices for iMessage and Facetime

http://macmost.com/setting-up-multiple-ios-devices-for-messages-and-facetime.htm l

FaceTime and iMessage not accepting Apple ID password

http://www.ilounge.com/index.php/articles/comments/facetime-and-imessage-not-acc epting-apple-id-password/

Unable to use FaceTime and iMessage with my apple ID

https://discussions.apple.com/thread/4649373?tstart=90

How to Block Someone on FaceTime

http://www.ehow.com/how_10033185_block-someone-facetime.html

My Facetime Doesn't Ring

https://discussions.apple.com/thread/4155326

For non-Apple devices, check out the TextFree app https://itunes.apple.com/us/app/text-free-textfree-sms-real/id399355755?mt=8

How to Send SMS from iPad

http://www.iskysoft.com/apple-ipad/send-sms-from-ipad.html

 Cheers, Tom 😉