Finally a reasonable suggestion. thanks raceman. It was beginning to appear that most members on this site believed that short people had no business driving a truck. Moving past the condescending, self righteous drivel, I did come up with a safe solution that it similiar to what you suggested.
I took a small block of wood, and from the hardware store I got a couple of heavy duty 4" metal hose clamps. They look like the hose clamps that hold your radiator hose on. I put the clamps, or you could call them metal bands, around the wood and the clutch pedal and tightened them down. They are on there so tight and secure that they made indentations in the wood. They dont budge, they are totally safe, and my wife in now comfortable driving the truck. She could drive it before, but had to practically slide off the seat to get the pedal all the way to the floor. The set up I have now is much safer.
I talked with a lady on another site, and she had done something similar. It is nice to hear that this is a common solution to a common problem.
One word of caution. They make a quick disconnect clamp. You DO NOT want this clamp. Get something similar to the one that is holding your radiator hose on. The 4" heavy duty clamps I got at the hardware store sold for only $1.50 each. You can probably get a small piece of 2x4 for free or real cheap. Take one or two pieces of 2x4, about 4 to 6 inches long, the metal bands, a few minutes of work and less than 5 bucks out of pocket, and you have a safe, reliable fix to this problem.
So, if you or someone you know is having difficulty reaching the clutch or brake pedals, here is someone offering you a genuine solution. I thought that is one of the reasons this site existed, to help each other. Rest assured, if you go this route, you will not be endangering yourselves, your spouses or the entire motoring public.