Jenny Everywhere

Jenny Everywhere aka "The Shifter" is an open source, public domain character. She was specifically created to be as such, when her creators could not find any other truly open source, public domain characters.

Jenny Everywhere is described both as existing in every reality and being able to shift between realities. This gives the character the ability to be inserted into the continuity of any existing or new work, such as various comics or webcomics. The concept may be extended to other media as well. She was originally created by Canadian comic book artist Steven Wintle, who uses the internet alias Moriarty, and co-developed by members of the Barbelith online community.

According to the character's website:

She has short, dark hair. She usually wears aviation goggles on top of her head and a scarf around her neck. Otherwise, she dresses in comfortable clothes. She is average size and has a good body image. She has loads of confidence and charisma. She appears to be Asian or Native American. She has a ready smile.

In the post where he first proposed the character, Wintle described her as:
If I had to compare her to anything, it would be like if Tintin listened to Le Tigre and joined the Fantastic Four. She's excitable, passionate, attentive, curious, and caring. Like Captain Marvel, she's just a really powerful kid.