Gwendolyn Catherine "Gwen" Tennyson is Ben's 10-year-old first cousin. She eventfully grows up to be a fifteen-year-old teenager in Ben 10: Alien Force, sixteen-year-old in Ben 10: Ultimate Alien and Ben 10: Omniverse. In memory-flashbacks (seen in Ben 10: Omniverse) she was eleven years younger. She is also Kevin's girlfriend. br br In the original series, Gwen shares a love-hate family relationship with Ben. Before discovering her dormant magical and Anodite powers, she helps Ben by simply using her innate cleverness and intelligence. She is known to be a capable gymnast and martial artist and has received a black belt in karate and taekwondo. At the age of sixteen, Gwen is a model student, and in Ben 10: Omniverse, she is shown leaving for an Ivy League College but drops in from time to time.