The newest arrival, named Bonnie Raye, was born at 6.43pm on Tuesday at the Royal Lancaster Infirmary where midwives had previously delivered 14 of the family's children.
Mrs Radford, 43, endured a 12-minute labour before giving birth to baby girl Bonnie, who weighed in at 8lb 4oz.
She was taken home to Morecambe, Lancashire on Wednesday to the delight of her family who 'were fighting over the first cuddle'.
Mrs Radford last gave birth in September 2017 and she promised at the time that it would be her last.
However, she announced in a YouTube video from May that she was pregnant again.
Speaking to the Sun about the latest baby arrival, Mrs Radford said: 'They were all fighting over the first cuddle. It’s such a lovely moment when you bring a newborn home and the others are all lined up ready to hold her.