I had the same revelation as you when I switched from my in-home weight machine to free weights, after listening to the smart ladies here! :K: I don't do lunges yet, but do squats and plies. I started with 5/8/10 weights, which gave me the cowboy too. After that quit hurting and a re-start, I did it with no added weight. Still got cowboy legs. SO yes, I think no weight is fine until you hear yourself saying, I need something more with this. Then add the weights back in.
And yes, (I may be wrong), but I do think we are more muscular just due to the fact of carrying 200+ lbs around on our frame day in and day out than someone in the low 100's. Just my opinion though.
BTW, is that a photo of you? No way I would have guessed you as 215 in that pic. In fact, you look like someone famous, maybe a country singer - Martina? Or maybe it's the nascar jacket making me think that!