So my understanding of terrain theory logic would indicate that all 3 of you have been exposed to a toxin.
Is it possible that the 3 of you were exposed to a contaminated starch or sugar? It's the toxin that certain bacteria produce that makes you sick. Many of these pre-made starches are like Petri dishes.
I'd wager food poisoning goes up in a high inflation environment. Did you visit any struggling businesses for a quick bite?
It can take a couple of days after eating for symptoms to show. I'd expect the kids to experience them first.
Germ theory would be to isolate from the baby & possibly your wife. Disinfect everything you dirty heathens!
Terrain theory would be to neutralize & excrete the toxin. CDS & activated charcoal would be my choice.
It's just a theory & I'm not certified to do or say anything.
💚🫂