Parents often bring little snacks for young children to keep them occupied and quiet in church. This is fine as long as it is discreet and quiet and the parent sees to cleaning up any leftovers. By the time a child is 3-4 years old this will most likely be unnecessary. And by the time a child reaches age 7 they are mostly capable of fasting the entire morning of Holy Communion (or at least cutting back on breakfast).
For those children who do require snacks during service, please refrain from feeding them, even a bottle, while in line for Communion, as they ought to come to the Holy Mysteries without food already in their mouths. Chewing gum is never appropriate in church.
