In families where one child has significant additional needs, another child often learns to take up less space. They stop asking for help with homework, stop mentioning their own worries, and quietly assume there is no time. The Sibling Who Feels Invisible is for the parent who has just noticed that quiet child and wants to do better without disrupting the care another child requires. With compassion and realism, Ivy Castellanos helps parents spot the small signals of a sibling fading into the background, find ordinary moments of undivided attention, and name the sibling's experience out loud so they feel seen. This is not a book about fixing anyone. It is a book about noticing, consistently and gently, the child who has learned to wait.