After living in Australia and contributing to television shows on Network Ten, Nine Network, and ABC Television, Wallace returned to Auckland in 1989 to work as a current affairs reporter and presenter on New Zealand television. She filed stories for shows such as 60 Minutes, 20/20, and Nightline. Wallace's work earned her the Steinlager Prize (for sports presenting) and the award for Best Tourism Story at the Qantas Media Awards in 1992 and 1993, respectively.
In 1996, she was a finalist for Best Presenter at the New Zealand Film and Television Awards. In 1998 Louise went on to act on shows such as Street Legal and Legend of the Seeker. She also worked as a presenter, fronting documentaries and features, as well as the New Zealand version of the international quiz show The Weakest Link in 2001.
In 2003, she appeared as a contestant on reality television game show Celebrity Treasure Islandand would serve as presenter and director for later seasons of the show. Wallace also directed the New Zealand edition of The Apprentice. Her most recent roles on television include stints on Shortland Street and Agent Anna.
In 2012, Louise was one of those behind the launch of Auckland theatre company Tadpole Productions where she has been currently acting in the show "The Pink Hammer".
Louise is married with two children and based in Auckland.