In 2005, she reacquainted herself with Mike in France. She moves to Walford after Mike's property scam fails, and lives with Rosie. Claiming she needs money for a medical operation, she cons her neighbours into paying for her breast implants. Mike comes to Walford, and when his mother Nora dies, she leaves £5,000 to Rosie. Mike persuades Dawn to pose as Rosie to get the money, and tells Dawn they will start afresh in Spain, but he takes the money and leaves alone.
After a failed attempt at a modelling career, Dawn finds employment as a barmaid. Ian Beale employs her in 2006, paying her to pose as his wife to impress business associates. During a function, she meets Rob Minter and they begin dating. She knows he is separated but Rob ends their relationship when his wife wants to give their marriage another chance. Dawn discovers she is pregnant with Rob's child and plans to have an abortion. May Wright, who is unable to conceive, asks Dawn to sell her the baby for £19,000. Dawn agrees, taking extravagant gifts and money in the process, but never intends to give the baby to May, and when Rob rebuffs her advances, she again plans to have an abortion. In order to stop her, May forces Rob to reignite his affair with Dawn, their real plan being to take the baby after Dawn gives birth. Rob eventually cracks under the pressure of the deception, confessing May's plan. In revenge, Dawn tries to force a miscarriage, but is unsuccessful. Rob is forced to prioritise, and leaves May for Dawn. May plays numerous vengeful tricks on them, getting Rob sacked, restricting their money, and evicting them from their flat.
However, Rob and May team up again, and Rob proposes to Dawn, suggesting they move away. He takes her to an empty house where she is handcuffed to a bed while May plans to perform a caesarean section. Dawn escapes after attacking Rob and returns to Walford, but goes into labour on the London Underground, later giving birth to a girl, Summer. While Dawn recovers in hospital, May sneaks into her room and tries to abduct Summer but Dawn catches her. Despite Rob's pleas, Dawn refuses to take him back, and May is arrested while attempting to see Summer.
Dawn struggles with parenting initially, leaving the care of Summer to her family, unable to accept the responsibility of being a full-time mother. Garry Hobbs proves a strong ally, helping Dawn care for Summer. She is happy to take advantage, but when he proposes during a trip to Brighton, she turns him down. Dawn hit it off with a local shopkeeper named Matt, and Garry walked in on them getting cosy in the hotel room, but Matt ran a mile when he realised she had a baby. Jase Dyer also shows interest in Dawn; both men compete for her attention, but she chooses Jase, devastating Garry. Jase proposes in June 2008 and she accepts; however, when Dawn starts favouring Summer over his son Jay Brown, Jase postpones the wedding.
In the midst of their arguing, Dawn is shocked to discover that May has returned, having had psychiatric treatment. Jase has unwittingly been working for May under her pseudonym Jenny, part of her renewed plan to steal Summer. May breaks into the Millers' house, knocks Dawn's brother Mickey Miller unconscious and locks Dawn in her bedroom, accusing her of being a bad mother. During a scuffle, Dawn breaks her ankle and May attempts to leave with Summer but Mickey intervenes. Devastated, May deliberately causes a gas explosion, killing herself. Mickey and Summer get out but Dawn passes out from the smoke and is saved by Keith's heroics; he enters the burning building and carries her to safety.
Dawn and Jase struggle financially. Jase begins working for gangster Terry Bates in order to satisfy Dawn's monetary desires. Realising he is involved in criminal activity, Dawn makes no attempt to stop him as she is desperate for money so she can have her dream wedding. The situation climaxes on Dawn's hen night, when Jase is set up by Terry, stabbed and killed. Dawn, who has only just decided that materialistic things are unimportant, discovers Jase's death on the wedding day. Jay blames Dawn for his father's death and rejects her. Dawn is distraught and turns to Garry for support, offering sex to him in a moment of vulnerability, but he turns her down. Dawn nearly leaves Walford following Jase's funeral but Garry convinces her to stay, so she moves in with him. Jay continues to antagonise Dawn, posting petrol soaked rags through her letter box. Dawn eventually manages to convince Jay that she loved Jase and thinks of Jay as family, and they call a truce.
Garry proposes to Dawn, and she is furious as she is still in love with Jase. Garry steals a car and flees. The police find the car abandoned by cliffs in Dover, prompting them to speculate that Garry has committed suicide. Dawn realises she is in love with Garry and announces this at his memorial service, only to be startled when he walks in. He gives her an ultimatum: be his girlfriend or he will leave Walford for good; she becomes his girlfriend. She gives evidence at Terry's trial and embarks on a secret affair with Garry's boss, Phil Mitchell. Minty discovers this, telling Dawn to tell Garry or he will. She decides to spare Garry's feelings and goes to stay with her mother. When Dawn returns, she resumes her affair with Phil, but he later ends the relationship. Minty threatens to tell the truth when Garry suspects that Dawn doesn't love him. Garry and Dawn talk, and return to the Vic, announcing their engagement.
Her affair with Phil is revealed by Minty to Garry, who jilts Dawn on their wedding day and decides to leave Walford for good. Dawn is persuaded to go after him, and sees him sailing off at a canal. She runs alongside him, telling him that she loves him. He lets her and Summer on the boat and they leave together.
First line: "I see the spots have dried up." (talking to her brother Mickey Miller)
Last line: "Wave goodbye!" (talking to her daughter Summer Swann)