Awesome! I am 5'9" and don't ride a WSD bike. The main difference for me was getting compact handlebars. Not women specific, but definitely better for women or any man who doesn't have big hands. I can shift and brake much better with these than the ones I had before, which were hand me downs from dh, much like yours hand me downs from your son.

My husband, who is also 5'9", which is not tall for a man, decided he also liked my handlebars and switched to the same ones.

The only other big piece of advice is get a professional bike fit, which you probably already know if your son is a Cat 2. It can make all the difference in the world to have the right fit, and if your bike is potentially not quite the right size for you, a good bike fitter can make the right adjustments to get it as close as possible.

Good luck on your new riding career. Haha! I'm 41 by the way.