Though Karna was not, his son was close to Pandavas

Karna’ son Vrishketu survived the war of Mahabharata and later he grew close to Pandavas. He also accompanied Arjuna to Rajsuya yagya. In the famous incident of Arjuna killed by Babhruvahana, Vrishketu was also killed.

Shri Krishna held Vrishketu in high regard, as he chose to revive him before Arjuna.

Full story is here

Family of Danveer Karna – Vrushali and Vrishketu