Call your pediatrici. If you think your child's eardrum has ruptured, they need to be examined. If the rupture is due to an infection, antibiotics will likely be prescribed and the child should be rechecked in 1-2 weeks. The hole usually heals quickly. If the rupture is due to trauma, such as a q-tip being inserted too far into the ear, an ear/nose/throat (ENT) specialist should be consulted.
Leave it alone. The vast majorities of burst ear drums will heal on their own in about 6 to 8 weeks as long as the ear stays clean, uninfected and dry. When showering put cotton covered in vaseline in the outside of your ear to repel water. If your ear hurts or you see drainage see your ENT doctor.