Some conventions arrange for professional Child care for the young children of convention members. This allows the parents to attend events that might not be appropriate for children. This service is typically not the same as a Children's track of programming at the convention, though they may have common elements.
There is often a professional licensing requirement to offer child care services in some cities. In any case, the convention should ensure it contracts with top quality providers to minimize risk and liability. Check references, check insurance, check experience.