I dunno what colors you're planning for the character, but I love the colors of the blade so far! In one of your sketches above, it looks like you have strings of light in her hair too. I think that looks great, and maybe they could help tie her to her weapon (not literally, just visually / thematically.)
The legs feel a bit anemic, but maybe that's why she needs those springy things to help her walk?
Anyhow, coming along well. Looking forward to seeing more on her. Good luck and have fun!