Space Girl

          I think you're doing great so far, when it comes to challenging yourself artistically and being honest about needing help, I want to help so here are somethings I noticed from experience. : )
         Many beginners don't know ( Including me when I started) That any style -cartoons and all, is referenced from real life, so even though things like the eyes and the hands or neck maybe smaller it's still in proportion - Have you ever see those things online that say "oh the wrist is half the size of the neck" for example, if your style calls for a skinnier neck then the wrists should change accordingly. does that make since? (It does seem like the neck is a little too thick.) I can't quite remember if that's exactly what it is but you should totally Google and study it -it's very fascinating lol
         Another thing is I can see is hands (obviously) I mean basically no one is good at hands - at least I'm not (lord knows I'm not lol) but the point is to get good enough that people can't tell ! It all goes back to references actually - even down to the stars in her environment- a real photo of the galaxy could help formulate a sense of how exactly the visible space matter is scattered around all around us.
         Last but not least- symmetry - symmetry is one of the basis of beauty and even if it's not perfect, It's probably not going to be totally chaotic (unless that's the point) in which you should make it more intentional, otherwise looks great, please keep it up : )