Scarlett's Sunshine on Sudden Unexpected Death Act This bill directs the Department of Health and Human Services (HHS) to address sudden unexpected infant death and sudden unexpected death in childhood, including through grants and by improving the quality of data pertaining to such deaths. Specifically, HHS must award grants to national organizations, governmental health departments, and other entities to provide grief counseling and other support services to families that experienced the sudden unexpected death of an infant or child. Additionally, HHS shall (1) determine whether to update the forms used to submit data about sudden unexpected infant or child deaths to registries and other fatality case reporting systems, and (2) encourage the use of such forms to improve the quality of data in the systems. Furthermore, HHS may provide other support to these registries and systems and may award grants to states and tribes for (1) supporting fetal and infant mortality and child death review programs, (2) improving data collection related to sudden unexpected infant death and sudden unexpected death in childhood, (3) training those who perform death scene investigations of children and infants, and (4) other activities to reduce or prevent unexpected infant and child deaths.