He had two younger trueborn brothers, Bran and Rickon, and two sisters, Sansa and Arya. Robb and Jon play as youths. Robb also had a "bastard half-brother", Jon Snow, with whom Robb shared a close relationship. Jon is actually Robb's cousin by blood, as Jon is the son of Lyanna Stark and Rhaegar Targaryen.

Was Robb closer to Jon or Theon?

Jon was Robb's brother. As where Theon was his best friend. He loved them both immensely, but he didn't love them the same.

Who was Jon Snow closest to?

Jon and Robb play with snowballs in their childhood. Of the Stark children, Jon was very close friends with Robb - given that they were roughly the same age, being regular companions in training and riding. He was also close with both Bran and Rickon, and was friendly rival to Lord Eddard's ward, Theon Greyjoy.