Hi Melissa!
I love kettlebell workouts so naturally I was intrigued by this program. Aren't we always looking for the next new thing!?
I never heard of Kettleworx until I saw your post. I checked out the website and it didn't take me long to decide that this is probably not a very good kettlebell workout. The biggest red flag for me -- nowhere on the website does it mention Ryan Shanahan's qualifications, so I sincerely doubt he holds RKC certification. The website refers to the Kettleworx program as the "global leader" in kettlebell fitness. I think Pavel Tsatsouline might have a different opinion about that.
http://www.dragondoor.com/pavel_bio.html
If your mom wants to try kettlebells I would recommend the following workouts, both of which include a good tutorial, are great for beginners, and the instructors are certified:
1.
The Kettlebell Way with Anthony DiLuglio and Beth Chamberlin
Here's a preview:
http://www.youtube.com/watch?v=CApy7Ykz5P8
2.
The Ultimate Body Sculpt and Conditioning with Kettlebells by Lauren Brooks.
http://www.ontheedgefitness.com/Videos/UltimateBodySculptandConditioning.aspx
HTH, and best wishes to your mom!!
ETA that I don't know how old your mom is, but I'm 55 and I don't have any trouble with either of the workouts I mentioned above.