If he’s going to address it, he should address it directly with Jane.
(And who knows, maybe he has.) If you say anything to anyone here, it should be to Jane to suggest that she apologize — not just to the wife, but to everyone who heard her.
Should I say something to Jane that she might be well served by apologizing again to the wife for her inappropriate behavior? His wife reacted entirely appropriately in the moment — she called Jane out on a horrible thing.
She’s continuing to react appropriately now; people being chilly to you is a reasonable consequence when you say a horrible racist thing, and Jane will need to live with that consequence.
If you do that, it shouldn’t be in the vein of “here’s how to smooth this over.” It should be “that was a horrible thing to say and I hope you’ll consider apologizing to everyone who heard it.” You don’t have a professional obligation to do that since you’re not her boss, but if you’re friendly with her, it’s hard to imagine continuing that relationship without addressing what she said.
In the course of the conversation, the concept of online dating / Tinder came up.
They beam when Spot enters the room and spend time greeting and cuddling him.
The cat eats gourmet food out of Royal Dolton and crystal.
I am quite sure that she told her husband, but knowing my boss, he’s not the kind to say anything to anybody.
Boss’s wife has come into the office a few times (which is standard; sometimes she’ll pick up and drop off something for her husband) and she is always appropriately professionally cordial to all of us, but still a little cool to Jane.