Maybe unrelated, but interesting, nonetheless...
https://www.youtube.com/watch?v=f0T1Rb_Q8cg
[LEAKED] Footage from campaign office of Huma Abedin and her husband Anthony Weiner
Published on Aug 23, 2016
[LEAKED] Footage from campaign office of Huma Abedin and her husband Anthony Weiner when news of his sexting scandal first broke. How does she react after finding out her significant other had been sexting behind her back with 22 yr. olds? She asks whats your press statement going to be? with zero emotion.
Wow.
Political marriage, political response.
The AppleID was used to setup the iPad. . . so that it could share their family data. When he set up his emails on the iPad, I am also wiling to bet he also set up her email on it. Therefore, their two emails are sharing the AppleID for archiving data. Voila. His and her data will be on both. It's a common practice among couples.
They did state they shared the Notebook. . . and if they did not bother to set a separate Apple ID for his or her separate user partition. . . it is a natural consequence of not doing that.