There are a lot of good things here - I especially love the way you're going for hard perspective, it's something that's not easy to do, and you're doing well.
I do think that you're certainly in need of new pens. In the first picture, it looks like your pen is drying out - especially in the hair area.
But you don't necessarily need thin pens to draw thin lines. If you "flick" your wrist, with a pencil or a pen, drawing a curved line, you can see that naturally, your line is thicker where you start and thinner where you end. Use that to your advantage. It's also necessary to use those techniques when using different pens, because you don't want your audience to see exactly where you switched pens ^^;; It should all look done in one pen.
I'm not proclaiming myself to be great at anatomy, but here's a redline for your third piece -
<3 In addition to the stuff I said in there, your eyes are overall too big. Search for some face anatomy tutorials - that's okay.
When the figure is holding a long pole - this is for your third and your last one, try holding something and use that to determine the pose. Use a broom, or a meterstick, or something like that. In the third piece, her left arm should be straight, and right along the pole. If you don't want her arm to be against the pole, it's more natural to hold it with the palm up.
here is just the redraw - if that sort of thing helps you ^^;;
All in all, there's a lot of great things going on. Of course, the mentor forum is a great place to find someone to give you tips as you go, but honestly, you're very, very much on your way. Good luck on your quest for new pens ^^;; and keep working. You've got a great sense of composition, and that's really to be envied.
