She is a static in contrary to dynamic character s. She stays the same throughout the course of the story.

Two independent clauses back to back is a run on, but these make great individual sentences. Nice work!

hHer personality doesn't evolve or transcend, s. She is flat unlike a round character that undergoes changes and can surprise the reader. Maria has simple personality and, uncomplicated as well personality—characterized by one personality trait.

Similar as above, one correct way to separate independent clauses is with a period. I took some stylistic liberty with the last sentence, but feel it pops a bit better now. These are good ideas you are writing. Nicely done.