Thinking about protagonist

The protagonist, Lena, has been floating around in my head for some time. She would be relatively unusual as a heroine in that she's not a pacifist princess, but nor is she a super action-woman. However many times I've rewritten the story, the gameplay and redesigned her appearence, Lena's personality has remained relatively consistent.
She is book-smart but inexperienced. Not so much naive, as she knows a lot, but she has experienced relatively little. She is somebody who thinks outside the box, but to such a degree that she has trouble sometimes seeing the obvious solution because she tends to go off on a tangent rather than thinking straight ahead. She is practical and not cowardly, but she is cautious and dislikes to jump into things or take risks if she hasn't weighed up the possible consequences.
This makes her somebody who likes to work things through in a slow, considered way. Unfortunately she is the one who gets thrown into the role of action heroine. She is not so much an unwilling heroine as somebody who isn't naturally inclined that way trying to muddle through as best they can.

I generally imagine her somewhere between 18 and 21, training to be a teacher, though I need to work through the exact details of the level of technology and social development of the setting, so how her training works and whether she's a teacher or a governess or tutor needs to be worked out. Despite her general dislike of unknown risk taking, she doesn't mind situations she's familiar with, and has a weak spot for wandering alone and climbing trees. This means that contrary to first appearences, she is not completely unsuitable as an action heroine. She does hate to fight though, and would rather run than fight back.