I'm writing about a fictional character and she has no common sense...?

She does stupid things without thinking through the possible repercussions of her actions and is easily impressionable as in easily convinced to do silly and sometimes dangerous things. I use this fictional character for comic relief in my stories but the more I write and talk about her the more I wonder if she might not be a little crazy or have some other disorder. Is this clified as a physiological/medical condition? I know there are bipolar people who are often impulsive but Olivia (the character to whom I'm referring) isn't like that. She just tries things she thinks will be fun and takes unnecessary risks. I've often described her as unbalanced. I need to know if I should feel guilty (as an author) for writing about such a character.