Well for starters. You could try taking a better quality picture or maybe scanning your drawings? Line art is very clean, but it's to simple. Especially for someone your age. I think you need to practice your Sonic anatomy. There are some great toturials out there! :3 HANDS, um, you may want to practice those! XD I can't tell the angle they're coming from. Simply put, I can't tell where the thumb or other fingers begin or end. Her pose could be a bit better. She looks more like a doll than a living, breathing thing. It's all about the body pose. For instance, the way you placed her eyes make her look like she's staring off into space. Her arms are stiffly placed at her sides. Simply put. She doesn't look "alive". But awesome job bro! keep practicing! :3
I thought the art was pretty original, so why did you mark it as not very original?