Bailey Baker made her first appearance on 10 January 2019, and she is the daughter of Mitch Baker and Dinah Wilson, as well as the half-sister of Chantelle and Keegan Baker. She is also the aunt to Mia and Mackenzie.
She is brought to Albert Square by Mitch Baker when he is fixing Karen Taylor's bathroom. Mitch leaves her in his van, until a drug addict named Craig breaks in, seeing an opportunity to steal. Bailey hits him in self-defence. Mitch sees the altercation and hurriedly gets rid of Craig and leaves Bailey to play with a football outside the Queen Victoria pub. She breaks one of the Queen Victoria's windows, prompting an angry reaction from Mick Carter. Mitch apologises to Mick and tells him that Bailey is his friend's daughter. After a chat with Karen, Mick visits Bailey's football club and apologises. Mitch and Mick get chatting and end up agreeing to help football coach Caden with the team.
In his travels through the Square, Mitch thought he spotted son Keegan giving a kiss to his 'new girlfriend' — but in reality, had no clue it was sadistic drug dealer Evie Steele forcing Keegan to kiss her as part of a drug deal. Back at the house, later on, Mitch and Karen were both enjoying Bailey's adorable card tricks, when an irritable Keegan stormed back in. Mitch teased his son about his new girlfriend, but a horrified Keegan snapped back that Evie was "just a mate" to cover his tracks. Mitch then ended up in the hot seat by accidentally revealing the truth about his and Bailey's bond. Mitch wanted to take Bailey home, but Bailey refused and asked why she had to go home. Mitch angrily snapped at her, saying "Because I'm your daddy and I said so, that's why,". Karen and Keegan both looked at Mitch in shock.
Bailey was the primary carer of her mother Dinah Wilson as she had Multiple Sclerosis which caused her to deteriorate rapidly. After Dinah had enough of seeing her daughter see her endure endless pain, she decided to take her life assisted by Karen Taylor to get Bailey out the house. Dinah left Bailey a birthday card as it soon approaching. In the aftermath of Bailey's mother's death, it came to light that Karen assisted in her mum's suicide. Bailey and her dad Mitch Baker were seemingly unable to forgive such an act, but they soon came around after realising she done it in Dinah's best interest