My in-laws stay cold even though I have tried to make peace. Should I stop trying?

Keep doing good without expecting an immediate return; sincere kindness is rarely wasted even if it is slow to bear fruit. The Prophet ﷺ said: “Indeed, gentleness is not found in anything except that it adorns it” (Sahih Muslim, Kitab al-Birr wa as-Silah wa al-Adab). Do not measure your efforts by your in-laws' coldness, but by Allah's pleasure. Lower the expectations that weigh on your heart, and keep up small, consistent services: greetings, simple gifts, help when needed. Keep a healthy distance if being there too often is painful, without cutting family ties. Pray for their heart and yours to be softened. Sometimes appreciation comes years later, or only from Allah. See in-laws.