Children who are people-pleasers often learned early that approval equals safety. Saying no can feel dangerous to them, even when they are uncomfortable. Start by validating this instinct rather than trying to change it quickly. Let your child know you see how much they care about others and that this is a strength, not a flaw.
Then gently expand the definition of kindness. You might say, “Being kind to others doesn’t mean being unkind to yourself.” Help them understand that boundaries are not rejection, they are information. Practice small, low-stakes boundaries together so they can experience that relationships often survive and even improve when limits are clear.