Board Thread:Questions and Answers/@comment-24578309-20140608193942/@comment-1362555-20140621173932

JoelleJey wrote: But they said by the Nickelodeon's TMNT Panel at NYCC 2013 that Venus isn't in the Season 2.

That still doesn't mean she won't appear at all. There have been rumors that she might debut in Season 3.