The basis of a great piece is here, the pose, facial expression and background are great, but the colors are my biggest problem with it.
Her dark brown top and outlines in combination with her reds being the same color as the background characters makes her blend in too much with said background.
I understand the decision to give her a dark reddish brown, since it’s a darker version version of one of her most prominent color. But I feel a dark blue or teal would have worked better, as blue is also super prominent in her design and would contrast more with the red background.
Speaking of the background, all I would change is making it a darker red.
Keep in mind none of this criticism is to try and demoralize you or to say your art sucks and you should quit. In fact, I generally love your art and it inspires me to be a better artist myself. I’m telling you all this because I want you to be the best artist you can be.
I hope this feedback helps you in the future.