For that I would recommend draw each thigh and make sure they have the same length, then each shin and make sure they also have the same length. Doing legs disproportionate in this perspective isnt unusual, happens to a lot of people, but not being able to notice or fix it shouldnt be a thing. Make sure to reassess your drawings before considering them "done" because a few things we comment here you already know, and it's really boring to tell you something I know you can fix by yourself :/ I feel like a dickhead
if you just cant notice these things by yourself then there is no problem, I'll keep telling you the same thing
sorry for sounding rude bye