As a director, she received a Daytime Emmy for voice-directing the music and dialogue on the children's animated series Madeline, in which she also portrayed "Miss Clavel" and "Genevive".

[2][3][4][5][6] After graduating from the American Academy of Dramatic Arts in New York, she moved to Los Angeles, where David Jacobs cast her as Sylvie in the first two seasons of Knots Landing on CBS before ABC asked her to join the second season of The Ropers as Jenny, the orphaned newspaper ‘boy’ whom Stanley and Helen found living in their attic; with Norman Fell, Audra Lindley, and Jeffrey Tambor.

for Teletoon Network, in which she voiced G.L.A.D.I.S..[24][20] In 2007, she was nominated for her third Emmy for casting and voice-producing the Discovery Kids and Mike Young Productions animated series, Growing Up Creepie.

[25] From 2011 to 2013, Stevie headed back to Los Angeles to cast and voice-direct two animated series for executive producer Bill Schultz: Guess How Much I Love You for Disney Junior, based on the children's book of the same name by Sam McBratney;[26] and Seasons 1 and 2 of Wild Grinders for Nicktoons,[27] starring skateboard guru Rob Dyrdek.

[31] Since then Vallance has taught children and adults how to do cartoon voice-overs in Chicago, New York City, Ottawa, Orlando, Miami, Atlanta, Toronto, Phoenix and Los Angeles.

[39] Vallance toured western Canada with this production for six years, performing at numerous venues including two runs at the Granville Arts Club in Vancouver and the Alberta Theatre Projects in Calgary.

[46][47][48] In 2004, Vallance debuted as a 'Jazz vocalist' in her hometown, Toronto, where she was accompanied by pianist Don Thompson, bassist Neil Swainson, and drummer Ted Warren.

She also performed for the first time in her birth town Montréal, at The Upstairs, with jazz pianist Steve Amirault, bassist Zack Lober, and drummer Jim Doxas.

Arranged by guitarist Pat Coleman, it features many other Canadian jazz musicians: pianist Ross Taggart, trumpeter Mike Herriot, saxophonist Tom Colclough, drummer Buff Allen and bassist Miles Hill.

[51] In 2009, Vallance performed in the Medicine Hat Jazz Festival for the second year in a row and was the featured vocalist alongside Ernie Duff and the Stardust Big Band, in and around Saugeen Shores, ON.