Place of Origin:
Legacy of the Daleks
Becca was a young girl living on Earth after the 22nd century Dalek invasion.
She tried domesticating a feral cat she named Serenity, hoping it could produce offspring that could minimise the rat infestation on her family’s farm. Before the Eighth Doctor left Earth, she gave him a tabby from Serenity’s litter. (Legacy of the Daleks)