They were not as hard as you'd think. I used her jeans to make the pattern. Lay the jeans down on craft paper or tracing paper and draw out the design. Don't forget the back of the chaps. You will need to add a little extra all the way around for hemming. Also, add enough at the top so that you can fold it over to make a tab. This will be used to attach the chaps through a belt. The picture below shows the basic shape of one leg. You will need to cut 2 pieces like this.
Measure the waist to make a belt. Allow for extra length.
The last part of the pattern you will need are small strips that you will use as ties to tie the front and back of the chaps together. I cut out 8 ties to make a total of 2 places on each leg to tie them in place.
First, you will hem all around the pieces that will go on the legs. Then you will take the piece for the belt and fold in half with right sides together and sew the edge shut.
Turn right side out and turn end in and sew shut. I went ahead and top stitched the belt.
Now you need to make the tabs for the chaps. At the top of the chap turn down enough so that the belt goes through and that it fits in the right places.
After this is complete I added the ties on to the sides of the chaps to keep them closed. To construct the ties, cut 4 pieces per leg. Fold in half with right sides together and sew. Turn right side out and turn end in and sew shut. Now you will sew them on to the chaps. I placed them at the top and the knee.
Use the belt to loop through the jeans and the chaps. I tied the belt in place, but you could add a piece of velcro or use D rings.
Tie them on to the legs and your child will be ready for the rodeo. Giddy up horsey.