Lilly Evans bursting into McGonagall's office almost every other day for the entire first month of seventh year –
"No, Miss Evans, you cannot." Minerva didn't even look up from her desk.
"But Professor! This time –"
"How many more times will you make me repeat myself?! Even the Head Girl does not have the authority to put the Head Boy in detention, or confiscate his pin."
"But Potter and his stupid –"
"And yet you still cannot Miss Evans."
And Lily storming out, frustrated, only to come back the next day after The Marauders' next prank.
Minerva McGonagall is certain Dumbledore knew this would be a headache to deal with, and orchestrated the whole thing to get on her nerves.
However when, after a month of constant pestering from an outraged Lily Evans, Minerva experiences a suspiciously peaceful week, she decides to call Lily Evans over to her office herself, to investigate the uncharacteristic change of behavior.
"… -yes, and so I have took, as you suggested, the mature approach and the Head Boy and I have talked things out maturely and came to an amiable conclusion as to divide our duties amongst us, and of course what he does in his free time is his own business –"
Minerva gave the girl a stern long inquisitive stare. "I see. And may I ask what weight to the negotiations it added that Mr. Pettigrew, Mr. Black, and Mr. Lupin have spent all of last week in detentions with Horace that you have apparently handed out to them, with the promise of more every day until they graduate?"
"Of course there has been made no such promise, Professor McGonagall that would be considered abuse of power. The Head Boy, however, seemed very happy to negotiate last night, and on an unrelated topic, Mr. Pettigrew, Mr. Black, and Mr. Lupin no longer have detentions."
Minerva gave Lily Evans a considering look. "I am thrilled to hear you took my advice to handle this maturely. Have a biscuit Miss Evans."
Because let's not kid ourselves; Lily Evans had to deal with the marauders for seven years and grew up with a Slytherin best friend – she learned how to handle herself the hard way, probably thanks to James pushing her buttons constantly. Now this is a main character I can get behind!
This is an intro to the real story :) will be up soon!