"Connie hated Umbridge very much over the next few days. Not only had she embarrassed her in her careers talk but then went and told her entire Defence Against the Dark Arts class. This made her golden reputation dip slightly amongst many, as it didn't take long for this news to get around the whole school. As head girl she was expected to be perfect and ambitious Connie always wanted to be perfect.
Connie took every opportunity to irritate Umbridge and Umbridge took every opportunity to annoy Connie. When Connie forgot to hand in a toy she had confiscated from a first year, Umbridge set her lines. When Umbridge was a minute late to class, Connie insisted that Voldemort could have had them in the time they were alone.
This was all very amusing for the rest of the class but then Connie took things one step further. She of course knew that there was a secret group being run by three fifth years and one evening slipped along to their meeting. Connie enjoyed what she was being taught although she was an advanced student herself.
By then end she was wondering why she hadn't come along before. Then she remembered that Umbridge didn't know about this and suddenly thought of a way to get back at her. Connie may have been head girl and a mature seventeen year old but when it came to people like Umbridge, she was seven years old again.
She cornered the three leaders after everyone else had left the room. Connie could tell they were slightly uneasy at being cornered by the head girl like this.
"Forbidden Forest, in the centre clearing, call the centaurs"
The three looked confused. Harry and Ron turned to Hermione, the brains of the group for answers. Connie only had one word left to say.
"Umbridge" with a wink she left the room. She hoped she'd done the right thing but Umbridge needed to be gotten rid of before Hogwarts could be at peace again.
Little did Connie know it would take a few years yet for Hogwarts to return to normal...
A bit short but I'm still getting the background out. I know this never happened in the books but I need Connie to have an enemy in Umbridge and to harm her in some way...