Is this story too mature for 6th grade?

Haha. I am loving this. Have you ever seen Law & Order: Special Victims Unit? 'Cause I almost had a heart attack at the use of the name Elliot and ADA Alexandra and then a last name that starts with a 'C.' This is extremely good. I am sure your teacher will love it. You might want to ask him/her just to be sure, though.