iTunes - digital watermarks

I've made my first couple of purchases of music from the iTunes store. As promised, my name and iTunes account info is embedded (watermarked) into the file. I understand the reasons why they do this, but now I am wondering.

My wife has her own computer, and her own iTunes account. If I import one of these albums into iTunes on her computer, is it then considered "pirated music?"

'Tis why it is a bad idea to use multiple Apple IDs within the same household.

My wife also has hew own computer, however, we have only a single Apple ID.

Same with Amazon books and Audible audio books - single ID for all book purchases to be able to download them to any of our Kindle devices &/or software.

I don't know if this is right or not, but I did iTunes> Store> Authorize This Computer... on both computers, from both accounts.