Email sender not matching address book

I have just noticed a change in my ipad 4th generation and iphone 5 running ios6.1. I uses to have have the email sender appear as entered in my address book for notificationson my home screen, inbox list, sent items and so forth. Also after openning the email it matches in the from section at the top. Now something has changed. The sender now only matches when i open the email in the from section at the top. But now notifications on my lock screen and in my innbox list show a different name that the sender used to sign up for their email. The sender is my mom. My dad set up her email using his name. For months it has been matching just fine but now why the change? It is strange because now the label mom only shows in the sent item list but not in the inbox list Now when i receive an email from my mom in notifications and inbox list it shows my dads name and only when i open the email does the from box change to mom. I have my mom listed as family in my contact card. I have the nickname added as mom and as well as only mom in the first name field. I don't know what has changed in my devices to make this happen. Strangly enough i have an old iphone 4s running ios7 and it still works with no problem. It lists mom in all areas. Inbox list, sent items list, notifications on lockscreen and so on. Because my ipad and iphone 5 are still under warranty i called apple and was told to reset all settings but that has not solved my problem. Anyone know how to fix this. Other threads with this issue offer no help but i believe were not communicated properly to the support members so I thought i would try.