How much trail are you planning to travel?
A family of 8 hiked the whole trail this year, the youngest was 2 years old and the oldest was 16 when they started the trail. Look up "Fight for Together " on YouTube. They vlogged the whole trail experience this year. Their last name is Crawford and they were from Kentucky/Ohio area near Cincinnati.
It has been done with smaller children. You just need to take it easy. On YouTube there is a channel called "Fight for Together". It's a family with 6 kids between 2 and 16 years old. They just finished it, but had some help. Also, the 2-year old wasn't permitted into the final leg in Maine, so they had to leave him with relatives. If they can do it, you can with proper preparation.
When I was 15, I hiked from Pittsfield MA to Rutland VT with my mother and my 8 yr old sister. When our four children were teens, we took them on the section through the White Mts. Now, 20 yrs later, my wife and I have finally done a "thu-hike" of the AT. If your kids are in good health, they should be physically able to complete it in 6 to 7 months, but they could not carry all their own gear and still keep up with an adult. The more important factor is whether they would be on-board with the emotional changes of being on the trail for half a year
This is a trip that will be fun but also tireing
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