the operation, causing a complication that leaves Toadie infertile. Worried that Steph is a threat to her marriage, Sonya offers Belinda a job as Toadie's nurse. Belinda quits after one day and Sonya's insecurities are exposed. She and Toadie begin attending counselling. When Sonya learns the community centre is being demolished, she asks for Tim Collins's (Ben Anderson) help as he is interim Mayor, but he double-crosses her. Sonya runs against Tim for Mayor and wins. On becoming mayor she is confronted by protesters, Paige among them, against removal of trees for the laying of a pipeline. Sonya hires Aaron Brennan (Matt Wilson) as her assistant, but after he allows Tom Quill (Kane Felsinger) to view council documents, Sonya is forced to fire him. Tom begins threatening the Rebecchis, taking a photograph of Nell and breaking into the house. The Lassiter's boiler room explodes, and Sonya realises Toadie is trapped under the rubble. He is soon rescued. Sonya's uncle Walter (Greg Stone) arrives in town to reconcile with her. Sonya decides to read the accident report about her parents' deaths and learns Walter was there that night. He then reveals that he is her father, and that he was arguing with his brother about telling her the truth when the car crashed. Sonya also learns that she has a half-sister called Zoe Mitchell (Nicola Billie Gullotti), who has leukaemia and requires a bone marrow transplant. Sonya takes a blood test, but is found not to be a match, so Walter suggests that Nell be tested and Sonya goes through with it behind Toadie's back. Nell is a match, but Toadie and Sonya refuse to let her go through with the transplant. Callum is also found to be a match and Zoe and Walter leave to continue her treatment. Sonya supports the creation of bike lanes in Erinsborough, but she faces opposition from Clive West (David Bradshaw). Susan is also upset at the decision as money will be taken away from the high school's remedial program. Someone vandalises Sonya's vehicle, a brick is thrown through Toadie's law office window, and snakes are let loose in the street, leading Sonya to think that she is being targeted by Clive. However, it turns out Steph is the target of a stalker. Sonya offers to be a surrogate for Steph and Mark, and they agree. The surrogacy is made public by Tim Collins in