In The Big Apple - Part 2, Heather insults Gwen numorous times, which Gwen insults her back each time.
In Boating in Italy, Gwen was displeased to know Heather was leading the challenge.
In El Bullio, Gwen says in the confessional that Heather's strategy on winning the reward challenge was stupid.
In Deep Blue Sea, Heather insults Gwen again.
In Japanese HiJinks, Gwen insulted Heather after she complained about the beds.
In Welcome to Hollywood!, Heather said that Hollywood was a home for freaks and weirdos and Gwen said "Welcome home Heather", which Heather glared at her for that. Gwen made a movie about Heather, showing Heather getting her head shaved from Total Drama Island, over and over and over again.
In Hassle in the Castle, when Gwen was excited about going to a scary castle, Heather said of course she would like castles since she's so scary she "Puts the Boogieman out of business". When Tyler told Gwen that Heather was captured by a ghost, Gwen asked him if that was a bad thing.
In Million Dollar Cook-off, Gwen said it was the greatest moment in TV history when Heather got her head shaved in Total Drama Island.
In The Final Season...Maybe, Heather stuck her tongue out at Gwen after Chris revealed her vote for Tyler. And demanded a recount when Gwen won.
In Duncan Tank, Heather was talking about how lovely her hair was, Gwen said "Your hair? Don't you mean the horse you got it from".
In Drama In The Air, Gwen told Heather to get a life instead of hurting people for tears and pain.
In Lazer Loser!, Heather got her alliance to vote off Gwen and when Gwen was voted off, she told her that she was a loser and to have a horrible blast off.
In TDAP Aftermath: II, Gwen called Heather a "wicked witch", when she was entering the aftermath studio. Gwen and Heather spent most of the episode insulting each other.
In El Bullio, Gwen cheered for Heather when she won the challenge.
In Amazon Drama, Heather asked for Gwen's opinion if her hair was messed up, after the natives captured them.