I'm afraid I know little of "cloning" these. They are such fast growers that I don't think most people clone unless maybe it's specifically to maintain traits. I would expect it to take more time to establish root growth than to start from seed just because they are so fast to grow. If your wife has producing plants, then choose the best fruiting one and let it go to maturity. Then plant the best seeds. Are these bush beans or pole? Go to a farmers market if you don't feel like waiting. You know, dry beans are green bean seeds that have gone to complete maturity. Otherwise, order the seeds online. Still faster than cloning, I'm sure.

I believe I have some wax bean seeds from a year or two ago. if you'll send me a private email, I'll drop them in the post to you.

Cloning is pretty simple in plants, and most plants that like to vine are easy to clone.

You want to make sure you cut a growth tip (where new stem and leaves are growing from). Get however many you want, but not so many that you really hurt the plant. I wouldn't take more than half a plant's growth tips unless you're willing to stunt its growth for awhile. Make sure each cutting has a few leaves to get it started.

Get your rooting system ready ahead of time, even if it's just some glasses of water. Set your cuttings out next to the water vessel(s) and then very carefully cut the stems a couple inches above where you made the first cut. Use a very sharp knife and cut at a 45 degree angle to the stem.

Immediately submerge the cut tip in water (you're trying avoid an air bubble being drawn into the stem.) If you really want to get fancy, cut it underwater. I don't, and I still get good results. Make sure you don't let the water drop below the end of the stem or you can kill the new cutting.

It can take a week or two, sometimes three, for the new roots to form. Once they're a couple inches long the new cuttings are ready to transplant into their new homes.

As long as the leaves are alive there's still hope for roots to grow.

Also, using a little rooting hormone helps a lot.

Here is a link that might be useful: My favorite rooting hormone