Summer is strong-willed, having a strong belief in what's morally correct, even in spite of Rick's belief that nothing matters. Standing strong, rebellious against any society she sees is corrupted. In the early seasons she was very petty, focusing solely on her popularity at school. After endearing so much pain from Rick, along with her family, she has grown immensely. Her worries shifted, as she grows ever more jealous of Morty's relationship with Rick.
Differences from in-show counterpart
The Summer of C-132 is much kinder and more relaxed than the Summer that the series follows. She is also less petty, and more agile, handling herself pretty well. Her future self also appears, twice, who is stern, strong, and resilient. In the comic series, Summer is also depicted as having a close relationship with Mr. Poopybutthole, that has yet to be explored in the series, but is very likely since he was such a close family friend to the Smiths.