Sue Radford, 37, gave birth to baby Caspar in just 16 minutes, bringing her total number of children to an impressive 16.
Mrs Radford, who lives with husband Noel and their children in Morecombe, Lancs, said she would now feel “l(fā)ucky” to have even more.
They are believed to be Britain’s biggest family, living in a former care home and using a minibus to get around.
Mrs Radford, whose family is not on benefits, told the Sun newspaper : “I just love being a mummy. We’re so lucky”.
The couple first fell pregnant when Mrs Radford was 14, deciding to keep baby Chris after they were both adopted as children.
They married when she was 18, going on to have Sophie, now 18, Chloe, 17 and Jack, 15.
Their enormous brood now includes Daniel, 13, Luke, 11, Millie, 10, Katie, nine, James, eight, Ellie, seven, Aimee, six, Josh, four, and Max, aged three.
The youngest members of the family are Tilly May, aged two, one-year-old Oscar and baby Caspar, who was born seven weeks ago weighing 8lb 8oz.
According to the Sun, the family currently spend ￡250 each week on food, consuming three loaves of bread, two boxes of cereal and 18 pints of milk per day.
They live in a nine-bedroom home, with the growing family being joined by their first grandchild after Sophie gave birth to baby Daisy.
Mrs Radford told the newspaper: “I know people stare. Some think they won’t get the attention they need. They don’t realise how dedicated we are.
“And maybe we’ll be lucky enough to have more.”
Other large British broods include the Shaw family, after parents Stacy and Tom had 13 children in just 16 years. Joanne Watson, from Guernsey, has 14 children.
The world’s largest family is said to be from Baktwang, India, where father Ziona Chana has 94 children by 39 different wives.
Mr Chana, who has said he is a “l(fā)ucky man”, lives in a 100-room, four-story home with another 14 daughters-in-law and 33 grandchildren.
