After graduating from Evan Hardy Collegiate in Saskatoon, Saskatchewan, Gaillard attended Ryerson University, from which she graduated with a degree in Radio and Television Arts. Gaillard then worked for a time at The Weather Network and as a game host for Toronto Maple Leafs broadcasts before joining The Score as their first-ever female anchor.
During her time at The Score, Gaillard received the opportunity to cover the 2000 World Series (a.k.a. the "Subway Series"). She was also hired as part of the Hockey Night in Canada team, and got to work rinkside at hockey games with her idol, CBC hockey anchor Ron MacLean.
In August 2005, it was announced that Gaillard had taken a job at Rogers Sportsnet. She made her debut on the network on October 4, 2005 at 11:30 p.m. as co-anchor of SportsnetNews alongside Mike Toth.