Don’t be too bothered by other people other than your child. Just need to make sure when your child starts understanding words, don’t let her teach your child nonsense.
You can reply her, it’s my job, cause I’m the MOTHER. Some elderly just speak without thinking but they don’t necessarily have ill intentions. Maybe when she say baby X is their Lee zai Zai again you can try can educate her by explaining your stand?
That way if she managed to understand where you’re coming from and changed the way she speaks, your life would be better. 😊