Most likely you authorized the BeBook to your id (it's a long standing gripe of mine that I hope to fix that we don't have a way to display the activation information for devices in ADE ).
There is currently no solution to allow you view content from multiple users on a single device.
On the computer however you can set up a different OS user account. So on your MacBook you could create an account for you, and authorize ADE in that account on your AdobeID, and this will not change/impact your wife's account which is authorized to her AdobeID.
Thanks for the idea, Jim.
We used to have multiple accounts on the one machine but have reverted to single accounts since my wife got her MacBook Pro (I'm very envious). Now that my BeBook is authorised to my account I'd better set up my account on the Pro.
But further information about the status of authorisation visible in ADE would be great.