Toilet paper
This will come in handy for the obvious use, but it can also be used for runny noses.
First Aid Kit
Stock your first aid kit will all the usual suspects, including Bandaids, ointment and anti-itch cream.
Hand Wipes
Your child will inevitably play in the dirt, pick up rocks and get dirty on the trail. Having wipes ready will ensure your child is not ingesting dirt (which can be harmful) by cleaning his or her hands before eating.
Drinks
Be sure kids stay well-hydrated during a hike. Consider bringing drinks they enjoy, like fruit drinks or hot chocolate (for colder hikes). To encourage children to drink water, try equipping them with a hydration pack. Kids may find this more "fun" to drink from and result in them drinking more water with less parental encouragement.
Plastic Bags
Bring at least two. One bag will be used for trash. The other bag can be used to carry any "collectibles" your child finds along the trail and wants to keep.
Trail Map
Having a map will help field questions of "Are we there yet?" or "How much farther?" that you will most likely be asked at some point during you hike. Show your child the map, where you are and where you are going. By involving children in the navigation of the hike, you will keep their interest.
Guidebook
Along the trail, children will stop to look at spiders, birds, plants and bugs. If you have a guidebook of the area you are visiting, you will be able to better answer questions along the trail, and provide a valuable learning experience for your child.
Snacks
Pack your child's pack with a few of his or her favorite snacks. Pick ones that will provide nutrition and energy.
Whistle
Place a whistle around your child's neck before the hike. Tell your child to blow the whistle if they get lost or come across an animal on the trail. This is a must-have item for safety on the trail.
Sunscreen and Bug Spray
Bring sunscreen even if you're hiking on a cloudy day. Reapply sunscreen after wiping a child's face. Bug repellent will ward off nature's creatures and keep your little one safe from ticks, chiggers and mosquitoes.