Mandy conceives Lip's baby, Katie, and after a year or so under the care of the Maguires, takes her away and moves in with the Gallaghers. However her father Paddy continues to supply her with financial support. She begins an open, long-term relationship with Lip while he is away at university, but finishes with him in series 5 after Lip's secret university girlfriend shows her face, she spends the whole series being rejected by every man she's attracted to until she goes on a blind date with a young man named Dex whom she gives him an E and sleeps with him, until she realizes she might have killed him so she and Karen Maguire (Rebecca Atkinson) try to dispose of the body, and spend the episode horrified with their actions, until Mandy decides to turn herself in without telling them who supplied her the drugs and who assisted her to dispose the body, she then learns Dex wasn't really dead but just passed out from the drugs, Mandy decides to come clean to him only for him to reject her.