Kara Zor-El, also known as Supergirl is Superman's cousin and a former member of the Red Lantern Corps.
She originally despised Kon-El, even giving him his name of "Kon" which in Kryptonian society is the word for abomination. Although after a long she began to see Kon-El as family as she does Kal-El.
Following Kon-El's death at the hands of Jon Lane Kent, an alternate version of Superboy who was the son of Clark and Lois. She is deeply affected by his death.