Yes, of course.
Here is an overview of the trail area. You can't see the trail in this photo, except near the end toward WL, where it veers from the road just a bit. In this photo, the green star signifies where the trail begins, and the red, the approximate area of the pool. The paved trail itself stops a distance from the pool, which I will show you in another photo. As Shan-man has already noted, there is a sand trail that veers off from the paved trail about 3/4 of the way to WL, and that trail goes toward the lake, and goes back to the WL bike rental and beach area, which is where the pool is. I have ridden this on a bike, and it is doable, but maybe not for little kids.
As far as distance, notice that I left the legend down at the bottom right of the photo. You also may want to look at the distance from the Ft. Wilderness marina to say the Meadow Trading Post. To me, it looks like this distance is comparable to the distance that you would travel on the trail. Not bad. I know that my kids did it on bikes way back when they still had training wheels, so it is not too far. It is a nice ride/walk, but it is not a short distance. Again, you can take a bus or boat as well.
Here is a close-up shot of where the trail begins at the Fort:
The yellow star is the Settlement bus stop. The green star is the beginning of the trail. The pink star is the Tri-Circle-D horse barn. You can see the pony ride area in this photo too. This is where you start on the trail.
Here is a close-up shot of where the paved trail ends at WL. The red star marks the circle where the paved trail stops. From here, you would travel across the cross walk that you see, and up the side walk. This is where the WL bus stops are. You can head back here, along the outside of the building, and reach the pool area.
Now you know how to get there, and where stuff is when you get there, so go have fun!
TCD