Antonia "Toni" McNally turned up at a bar looking for Jackie Coulson. Jackie has been having an affair with Toni's husband Sean McNally who is a major player of the McNally mob. She follows Jackie into a toilet and shoots her, and is sent to Wentworth Detention Centre on remand.
She immediately gets to work buying off the women. With Bea Smith out of the way temporarily, she takes over from Monnie as top dog just to prove she can do it. Then instead of operating the steam press, she pays Kathleen Leach to do it for her.
Toni's connections to Wentworth's underworld means that she is able to pull some strings to get Erica Davidson to give her some special priveleges, and also to get Jim Fletcher away from the prison on leave.
Toni begins smuggling in alcohol and drugs for the prisoners. Upon release, Bea strikes up an uneasy friendship with Toni, until she learns about her drug smuggling operation, causing Bea to immediately attempt to take the Top Dog position. Eventually Bea stirs up some trouble, but Toni decides she wants no part of it especially as her trial is approaching.
At her trial, Toni is found not guilty of the murder of Jackie Coulson, however her huband Sean rejects her.
Jackie Coulson's daughter Roslyn, tracks Toni down. Hearing that she was found not guilty, she took the law into her own hands, shooting Toni in front of the courthouse. Toni is taken to hospital and dies at the end of episode 64