Here's a fairly decent "short" answer that would disagree with you: What is the difference between christian and catholic?
And then we're not even getting into deeper issues like excommunication in Catholicism that basically means a one way ticket to Hell, whereas in Christian belief systems this is impossible, as only the believer can condemn himself by turning away from Christ.
The same answer here: The Difference Between Catholicism and Christianity
Here are two answers: What are the differences between Christianity and Catholicism?
Answer 1: Sees them as both being Christian, in a round about sort of way.
Neatly sidestepping the issue, as always.
I prefer the first answer at the beginning of the post, but it's quite clear, even in the Catholic answer, that whether you see Catholics as Christian or not really depends on how you define the word Christian. So, I put it to you, that her husband isn't quite the idiot you seem to think he is. :2cents: