iPad : how to stop text messages and email from iphone6 going to ipad

If you don't want calls or messages for your iPhone on your iPad, iPod touch, or Mac, you can remove your phone number. There are two ways to do this:

• On your iPhone, go to Settings > Messages > Send & Receive. Select your Apple ID and tap Sign Out. Then go to Settings > FaceTime, select your Apple ID and tap Sign Out.
• If the phone number that you want to remove belongs to an iPhone that you can't access, change your Apple ID password. This removes all phone numbers from your iPad, iPod touch, and Mac. Calls or messages for the removed numbers won't appear on those devices anymore. 

If your signed in with the same Apple ID on both devices that is normal. If you don't want email going to the iPad delete the account