Giving the gifts cards anonymously, especially because your motives seem pure, is a wonderful idea!
I agree that giving cash/cards anonymously sounds like a wonderful gesture.
If you’re worried they’ll still feel insulted or embarrassed by this, is there anything minor you could ask the wife to help out with, then insist she accept payment?
That the gift be anonymous is a good thing, especially if you value their friendship. It sounds as though your instincts are good. Indebtedness between friends can alter the relationship- and not in a good way.
One of my neighbors was having a hard time last year. Another neighbor borrowed his truck to move something and returned it with a full tank of gas. That small gesture was really appreciated by the first neighbor.
I’ve done this - I have a good friend who had a terrible 2010. Her husband walked out on her and her daughter after she’d been a stay-at-home-mom for over 10 years. She was having no luck getting a good job and had very little means to put food on the table, so I put some giftcards to places like Target and our local grocery story in an envelope taped to her door.
I felt a million times better about doing it like that, as she’s the type of person who would worry to death how she could thank me and how she’d make it up to me, and I didn’t want her to worry about that. Using the cards to take care of her and her daughter was the only thanks I needed to know about.