We did get Kat (the 5 year old) a little pack to carry some things in so that she'll be like everybody else.

We've been thinking about the speed issue and distance. The site we're reserving is only 3 miles from the trailhead. There's a split about a half mile in though and you can continue straight on toward the campsite or you can take a loop of trails that covers about 10 miles. Right now we are talking about breaking off into 2 groups at the split and my fiance and I can take Kat on to camp where she can enjoy exploring the creek while the older 2 go with their dad and uncle on the longer loop. On Saturday we'll try having everybody together and see how they do. Thankfully the group is big enough that we can break up into smaller groups if we need to.