It was an early 2000s comic book, most surely from the USA. I think it was the first number in a series. Four high school boys and girls find the body of a female superhero in the woods.
Most of the story was about the lives of teenagers. One boy was a conflictive student with a dysfunctional family, one of the girls was obese.
I've been searching the internet for "kids find dead superhero woman in the woods" without finding anything relevant and I don't recommend you to do the same. Bing gives many results with pictures of "dead women" and "dead kids". I'm afraid it's an usual search.