Hiya,
First off, I'm not an expert.
But I THINK that you can't really choose how your legs will "develop" if you are working out. I think it is genetic. Some people have shorter legs, and have muscles that will develop that will "seem" bulky looking (I do.) If fat is not the issue, and you enjoy walking and jogging, then why not just appreciate what you have? Your legs say, "I am a strong girl who knows how to run" instead of "I am an anorexic party chick" (the message I get when I see those slender legs in Cosmo or on celebs.
I like my newly developed muscly legs. They are not masculine, but they are not model-thin, either. They are STRONG!