My son still has a scar from the day my drunk ex-husband decided not to take him to the doctor after an accident.
People knew for a year that he was an alcoholic before I found out. Likewise we spent months trying to figure out what was wrong with my mother, who had never been a big drinker but started to self-medicate after menopause. We were literally telling her doctor "it's like she's drunk!" And never considered that she was ACTUALLY drunk.
Net net, don't assume her husband knows anything. It's worth reaching out to express your concern.