Julie Wilson was James Wilson's third wife, until she had an affair and they got a divorce. She was an unseen character.
Wilson met Julie shortly after his divorce from his second wife Bonnie Wilson. At the bachelor party, Wilson met Karamel for the first time and was reunited with her at Chase's bachelor party. Wilson and Julie were married sometime before the start of Season 1 and broke up in Season 2. They lived in an apartment and had no children.
It is clear that Wilson's friendship with Gregory House strained the relationship. In one case, Wilson left a dinner party when House was in trouble.
The Wilsons had a maid, Lady, whom Julie fired after their break up because she didn't want anything around that reminded her of Wilson.