If there's a difference in length it's negligible, and theyre not too close together. The problem is theyre half way down her thigh. her calves are at least two times the length of her upper leg. If you can't see that you should definitely study some anatomy :|

 I wanted to make my style a bit more realistic with the dithering but i can now see anime style should be more simple.

I should start small too as I lost my view over it.  

and the black lines arent that cool either I will change the color for something more that fits the skin color.

 now that i look at it

they arent the same length and too close together ( ' 3')

 I know you said your anatomy isn't great, but just take a second to look at where her knees are...

I think you should start smaller.  At this scale its too much time to pay attention to the pixel level details, and as such your lines arent as good as they could be.  If youre going for an anime look, then ditch the dithering, its just adding noise, and anime tends to not blend between shades anyways.  Not a bad start though, but go smaller if you want to learn pixel techniques.