Sadly Tina, I think Mia is a little more ummm....demonstrative about things if she's disgruntled. I'm not undermining how bad Flora was, because I know she was a nervous girl, but Mia has done some SERIOUS damage to the fosterers face before. She had to go to hospital to get the wounds sorted.
Of course, Mia could just be a stressed out lady who will chill out in time; who knows.