My niece is making a big mistake with her son.

Care and Feeding is Slate’s parenting advice column. Do you have any questions about care and feeding? Send it here.

Dear Care and Feeding,

I’m a firm believer in keeping your mouth shut and minding your own business… but I’m very worried about my four-year-old great-niece (as is her grandmother, who is my sister).

My great-niece’s mother often gives her soda and chips to eat instead of healthy food. A while back at a family party, someone said something about this. And her mother (my niece) said, “This is all the little girl will eat!” I’m worried that this is part of a pattern – my sister has told me other things about the situation with this little girl – there is no discipline and she is not potty trained. I’m worried that I’ll say something to my niece, thinking that she will just push me aside, like she has threatened to do with her mother. But I’m also very concerned about this little girl’s development.

—The mouth is closed, but worried.

Dear Mouth Shuts,

How (and if) you can get involved here really depends on how close your relationship is with the mother, your niece. From what you’ve told me, you’ve only… I heard from your sister You were not a witness to it, I don’t even know if you witnessed the confrontation at the party. I don’t think you are close enough to your niece to be able to say anything directly to her about this.

I agree with you that it sounds like a problem – healthy eating is the foundation of health. Try this if you can: without mentioning anything about discipline or healthy eating habits, babysit your grandniece for 24 hours. You can teach her some healthy eating habits while also watching the child’s behavior up close and perhaps understanding where your niece is coming from. If you notice a lack of discipline and potty training, you can bring these things up with your niece in a constructive way, perhaps even just empathizing with how difficult it can be to raise a little one with these challenges.

There are probably many other authorities in this child’s life who can provide some guidance. Does your niece have a partner? Does your grandniece go to preschool? How about a pediatrician? These people are likely to have a greater ability to reach your niece. and He or she will do it without you intervening. You can help by being there to provide support and model healthy habits, without giving advice or criticism. Parenting is hard and lonely, and taking advice from people who have no obligation to raise your child is difficult. Focus on being a part of the child’s life and a broader support network, not shouting instructions from the sidelines.

—Greg