We finally visited the d'Orsay on our 4th visit to Paris last month. It is def more manageable in size than the Louvre, and lovely to see some of the great works of art in person. We ended up being there on the Thurs evening it was open...now, it was April, but there wasn't much for crowds. But then again, I don't know what it's like thru the day during summer months.
We've done parts of the Louvre twice - it is more than paintings and sculptures, tho that is much of it. We also revisited the Louvre last month, and did go to see some of the famous works again, but also went to the wing with the decorative arts - beautiful furniture, exquisitely decorated snuff boxes, tea cups, crown jewels...there is an Egyptian wing also, amongst others.
I'm not an 'art' person either. After 90 min in a museum, I'm ready to pull my hair out. I'm not into art theory, and won't stand there for ten minutes gazing with rapture upon a painting. But, we also did the Rijksmuseum last month, and I finally found a way to enjoy paintings. I look at the small details. Like the folds in the clothing. The delicate jewels...the brushstrokes. I'll look for something that makes me laugh - like one painting of a naked Adam and Eve, and the look on the faces of the animals - like - Adam, put on some clothes! Or the 'v for victory flashing' buff baby Jesus in one painting - he had more abs that some bodybuilders! Or looking at the insects - the bumblebees and butterflies in a still life painting, the small details. So I actually found by doing that, it heightened my enjoyment - I know, it's ridiculous, but it's the little things. I've stared at many paintings, but this was the first time I really...enjoyed...it by any means. So that could be a way for your wife to enjoy a museum visit.