I like the style of this!!
I am assuming her pants are meant to be puffy? If they are meant to be form-fitting then I would have to say her calves look... large. Her left leg doesn't look bent like she is walking, but more like she is doing a lunge. Also, I know this is totally nitpicky and might just be a personal preference... but you said she is a tough tomboy character? In my experience females that have a tough, hard, boyish personality don't often wear tube top bras. :\