My leg muscles are really uneven, How can i make only one stronger?

I run track and cross country, XC is 2 miles, and in track i run 400, 1600m relay (another 400) and the 2400 or a mile and a half. I also triple jump anyway the muscles on my starting/jumping leg on the whole leg are noticeably larger that the left. What exercises can i do to beef up my left leg? they truly do look funny when i flex. I'm a girl and i don't min like being as cut as i just don't want to be lopsided anymore.