There is a difference between targeted offers and pre-approved offers. I get targeted offers all the time that I don't qualify for, due to 5/24, 24 months, etc. Sometimes even for a card I already have open, even though it's a card with T/C that you can only have one at a time. The computer randomly sends these out without bothering to check if you actually qualify.

Pre-approved offers are different, if you get one you are sure to be issued a card and it's stated bonus. But those are quite rare, and clearly state "pre-approved" I'm guessing yr wife got the former, not the latter, so it's a no go.