My brother and I suspect that our sister-in-law has either embellished the extent of our niece’s food allergy or made it up completely. The same holds true for the child’s “asthma.”

Our brother, who is married to the mom in question, is not one to make waves. They live across the country from us, so we do not see them often, and when we do it’s usually not conducive to discussing this. This little girl — home-schooled and an only child — only knows what her parents tell her. There is much joy to derive from food, and this kid has it in her mind that a lot of food is dangerous. My brother and I believe that our sister-in-law does not want her child to grow up and one day leave her. My sister-in-law’s brother still lives with their mother. He is middle-aged, of sound body and mind, but the mother kept him in the nest. We feel strongly that my sister-in-law is repeating this with our niece; if she has severe allergies, it makes it easier to explain the home schooling.

My brother and I were thinking about calling my niece’s allergist to let him know that we are skeptical. I would imagine that he must have an obligation to cease treating someone if there is no evidence of disease. That said, we don’t know if my niece sees the allergist often. We have tried to bring it up with my brother, even sarcastically asking to see the medical chart, but it doesn’t lead to anything productive. My sister-in-law needs to be exposed, but we certainly don’t want to damage the bond between mother and daughter. Name Withheld

My response: Another message with no question. Thank you for sharing!

The New York Times response:

You begin with a suspicion: That there is something wrong in the relationship between your sister-in-law and her daughter, and that something shows up in various ways but especially in false claims about your niece’s health. Then you develop a theory about why your sister-in-law is doing this, and you end up convinced that she “needs to be exposed.” But you don’t offer real evidence to support this hypothesis.

There is a condition listed in the Diagnostic and Statistical Manual of Mental Disorders (D.S.M.-5) called “factitious disorder imposed on another.” Its less formal name is Munchausen syndrome by proxy (Baron Munchausen was the protagonist in a tall-tale collection from the 18th century). To judge from TV medical dramas, the syndrome is commonplace; people have been captivated by the figure of the bad mother. Yet it’s rare. So bear in mind that suspicions of such medical child abuse seem to have outpaced the empirical reality.

I’ll grant that anxieties about food allergies, too, may have outpaced the empirical realities. To go by the C.D.C.’s most recent numbers, something like a dozen Americans die of food allergies each year. The C.D.C. estimate may well be low, but we’re more than twice as likely to be struck dead by lightning. And reputable studies have suggested that food allergies are overreported and overdiagnosed. (What experts are most confident about is that we need better data than we have.) Even if you are correct, however, what is needed is help for your niece, not exposure for her mother.

How to help? Intervening in others’ relationships, even when you are in the same family, is a large responsibility. You see your brother and sister-in-law rarely and apparently can’t get through to them on important matters. Going behind their backs to talk to their daughter’s allergist — again, assuming your suspicions are well founded — isn’t going to solve the problem. Besides, the allergist has a duty not to discuss any of this with you.

The one person whom you could usefully talk to is your brother. Although people can be blind to what is going on in their own households, the fact that he doesn’t share your anxieties should make you wonder if you’re right. Still, you should convey your worries to him, seriously and without sarcasm. And after that? You should probably step back and keep your own counsel.

You don’t mention evidence of harm to your niece beyond deprivation of the pleasures of a wider range of experiences. So I would be wary of hammering away at an allegation of this kind, not least because you could end up being exiled from your brother’s life altogether. And that would mean you wouldn’t be around to offer your niece advice once she’s old enough to make her own decisions.

I was at a party where someone was telling a racist joke. I removed myself from the group of people surrounding that person. (Other people, but not everyone, walked away at the same time I did.) A friend said that I should have said something while the person was telling the racist joke.

I was an invited guest in someone’s home, and I did not think it was appropriate for me to say anything. I felt that walking away was enough of a statement. My friend said I should have said that I found the joke offensive and stopped the person from continuing. The people who stayed to hear the joke were all laughing. Should I conclude they are racists? Name Withheld

My response: I wouldn’t, based on the scant evidence you shared.

The New York Times response:

Here’s a rule of thumb: If you wouldn’t tell a joke about black people in the presence of a black person, you probably shouldn’t tell it. (Likewise for other identity groups.) Humor of this sort rests on stereotypes that often come with a painful history of hatred or contempt and risks affirming those attitudes. At the very least, such a joke raises the question of whether the laughter relies on unconscious prejudices. There may be contexts in which jokes about race help disrupt such attitudes. But you wouldn’t have regarded this joke as racist if that were its effect. So it was ill judged, at best.