This is a fun read, but also thought-provoking.  Your characters have depth and direction.  I like Lily giving lip-service to the 'strong woman' thing, yet agonizing over a 'throbbing, oily ZIT!!!!'

And I like your Marauders, especially Peter.  He's a lot smarter--more the other boys' equal, at least in intelligence.  I like that James recognizes his feelings of being left out of the action and placates him by entrusting him with his precious Invisibility Cloak.  Shows James to be a little more sensitive than most writers portray him.

You express yourself well.  I could just see that Quidditch match with all the Snitches flying around, and the Marauders laughing their arses off under the stands.  And a bunch of self-righteous Hufflepuffs and Slytherins arguing their cases with the beleaguered referee.  Great idea!

 And--oh!--what is Madam Hooch going to do?!!  Hell hath no fury like an embarrased witch.

I really like the interaction between the brothers here, that they would sneak around to keep their relationship intact. I also like your portrayal of a more vulnerable Sirius--I am quite sure he had his moments, and I enjoy seeing him depicted as something besides an arrogant jerk!

I am intrigued by your opening chapters and look forward to more.

Wow, excellent job! I loved the part about the toothpaste! I'd like to read more. :) 

Woah. Creepy end there. I loved the beginning with the boys... you really captured their youthful cameraderie. Or however you spell it.

Nice job.