The new arrival will be joining big sister, three-year-old Alaia-May.
A friend of the family told The Sun: “They’re delighted. Everything went really well and they can’t wait to get home.
“It’s a beautiful little sister for Alaia-May and they will announce a name soon.”
‘The Saturdays’ singer began dating ‘JLS’ star Marvin in March 2010. They moved in together just three months later and got married in 2012.
Humes announced her second pregnancy with a beautiful maternity photoshoot, which she shared on Instagram in November 2016.
“Ten tiny fingers, ten tiny toes, but who are you? Nobody knows,” she wrote in the caption.
Congratulations to the family!