I think it does man, I don't know many girls with balls.
You don't need to stretch for 20-30 minutes. Stretch 2x a day for brief periods on tight muscle groups only until you get more flexible in the range you want. Then drop to stretching 2-3x a week. You don't need to do it a lot to maintain.
Also, why not wait until you lose ROM in your muscles? I mean, you don't want to push yourself further than you need. I used to be able to fall into splits even when I squatted a good amount, but I stopped caring about it so much 'cause it's not functional for me in any way.
In fact, stretching too much can be a bad thing. Joints will get too loose and such.