Well, consider a situation where a young child is sucking on a lollipop as mom takes them to a community event. Mom is introducing the child to neighbors and the child is enjoying the lollipop. It's a positive and family - friendly public scenario that doesn't cross any boundaries.
Another story could be a toddler who is sucking on a juice box while holding mom's hand in a park. Mom is chatting with a friend and the toddler is happily sipping the juice, which is a common and proper scene in public. There's no inappropriate behavior here, just a normal family - out - and - about situation.