Gwen Stacy was Captain Stacy's daughter and Spider-Man's original love interest before Mary Jane came around. the Green Goblin, who knew Peter's secret identity, kidnapped Gwen and dropped her out of a bridge, and despite Spider-Man's web reaching her before she hit the ground, the shock made her pass away. The loss of Gwen was one of the biggest tragedies in Spider-Man's career.
Her only abilities are to be able to kick and punch.
In Spiderman 3, she is portrayed by Bryce Dallas Howard, who also portrayed Claire Dearing in Jurassic World.