Thanks for your answers and tips, I'm gonna focus on construction a bit more for the next ones! 
I'll try to forget colour as well... For now
There are some issues though: a bow shouldn't be pulled with an elbow that high up and her left arm seems drawn like it's her right arm. I also think her back is weirdly bent. Her actual right arm is bent in a way that is not possible.
Of course it is :-p I lack a bit of retreat on that one, you're obviously right I'll try to correct it. I think the problem on the left arm is partly due to the curved line cutting the two parts of it, actually.
I also tried to work from reference for that right arm but failed anyway; It's hard to find some good resources for that type of arm-positioning.
Thanks a lot for your feedback! 
One think I would say is as you do them, try to work in studies too. Either as your daily sketches, or along side with them. You will learn and grow much faster if you train both muscles at the same time!
Do you have any good ideas about that? 
I've been working a lot on quick gesture drawing last year, generally 1-2-5 minutes long. I'm a bit tired of that type of exercise, don't hesitate to give me your best training/study ideas. 
