Gwen Stacy

High School
While Eddie Brock might have been Peter Parker's childhood friend, and Harry was a good friend he met in high school, Gwen was Peter's oldest constant friend, someone Peter had known since Middle School. Much like Peter, she was kind of an outcast, and they were drawn together like that, though only as friends. While Gwen did harbor a crush on Peter, Peter was simply too immature at that point, and by the time they were seniors they had been friends for so long that Peter didn't feel comfortable wanting more.

But when Peter became Spider-Man, he of course didn't tell anyone, and this started to drive wedges in his dealings with his friends. And when he got the Daily Bugle internship it just made matters worse. This hurt Gwen possibly most of all. And when Peter blew off plans with Gwen in order to investigate Oscorp after the Scorpion incident, Gwen very publicly told Peter off. At this point Peter decided enough was enough, being Spider-man wasn't worth it if he kept hurting his friends, so he made the decision to privately tell Gwen that he was Spider-Man, and then quit. Gwen was taken aback by this sudden revelation but was overjoyed that everything suddenly made sense. She convinced him to keep being Spider-Man and she became his sole trusted confidant, causing their relationship to bloom into something more romantic.

Death
But then the Sinister Six incident happened at the end of Peter's high school career, which drove Peter and Gwen apart. The Spider-Man relationship had been strained several times prior, but the death of Gwen's father just broke it. Taking advantage of this, Norman Osborn offered himself to be Peter's mentor. Peter being kinda lost and confused without his oldest friend and confidant, accepted. For the summer after high school until college at Empire State University begins Osborn acted as a guiding hand in Peter's development, but Peter eventually realized his ulterior motives. Osborn revealed to Peter that he knew he was Spider-Man, and that he was the Green Goblin, the one super villain that Peter had never properly defeated. Osborn gave Peter one final test of loyalty: find and kill Mendel Stromm. If Peter refused, he would start killing all of his loved ones.

Horrified and just about ready to give up Spider-man altogether and go to the authorities for help Peter rushed to find Gwen Stacy. Still not comfortable with talking to him Gwen deliberately avoided Peter, and before Peter could reach her, the Green Goblin confronts him to ask him how his hunt for Stromm was going. Peter told Osborn his plan to give himself up and go to the authorities, and, well, nothing good happened after that. Osborn reached Gwen Stacy first, and Spider-Man chased him down to the George Washington Bridge. The Goblin tossed her off the bridge, and Peter wasn't successful in saving her--her neck is snapped. She died before ever reconciling her relationship with Peter.

In his grief Peter hung up the webs for several months. It didn't help that his Spider-man costume was mostly destroyed in the battle and he had lost his webshooters, but he just couldn't bring himself to start up again. When Gwen died Peter got her locked chest she kept some of the extra Spider-man equipment Peter gave to her for safe keeping, but Peter didn't dare open it. Not until six months later did Peter open it and find a new Spider-Man costume that Gwen had been working on after they split up, indicating to Peter that she had intended on rekindling their relationship. Realizing that she had hope for their relationship, Peter starts his career as Spider-man again.

Gwen Stacy's death would forever leave a mark on Spider-Man's history.

Design
"But yeah, like I said, I tried to take those two Gwens together and combine them and ended up being very happy with the design. Thought about giving her glasses like in Spectacular but decided against it. Like the others this is supposed to be her roughly as a senior in high school." - GM