McAlpine was born and grew up in
Bury. She is of
Scottish and Irish descent, with a grandfather from
County Kerry and a grandmother from
County Sligo. As a young girl, she used to put on shows on the patio for the neighbours, charging them 50 pence apiece. She did song and dance routines, copying groups like
Bananarama. Her father, Thomas McAlpine, worked in mental health and was awarded the
OBE for services to mental healthcare; he died in March 2017. With his encouragement, she took up amateur dramatics at the age of eight, when father and daughter appeared together in a
pantomime by the Bury Parish Players. She was the fairy and he was the dame. As a teenager, she joined the Carol Godby Theatre Workshop. McAlpine's parents separated when she was young, after which she lived with her father. She has one brother. ==Career==