I have a 3 year old son and I would not recommend taking small children on the hike. There are a lot of creek crossings and some uphill areas, I think it would be too much for them.
There are some places where you have to climb some very steep and wet areas. I wouldn't think that carrying a child would be feasible on this hike.
I'm thinking it might be best to get a babysitter. Those stream crossings are pretty gnarly and a complete dunking in icy water always a possibility.
It's really down to how comfortable you are. There were people carrying their children in their arms and the wearable suit things strapped to them. It's not really that bad, it's just a long hike for a kid. If you do go, bring them plenty of water and snacks.
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