The pop star and actor announced the happy news to Twitter on Sunday night (Dec. 6).
"SURPRISE! We are pleased to announce that we recently welcomed baby number two!" she wrote to her shocked followers.
"Congratulations. No wonder you've been quiet on here," replied a fan.
Baby Tora is the couple's second child. The name means "Goddess of Thunder," or the "female Thor," and Spearritt seems to have hinted at her second child's impending arrival with a cryptic picture on her Instagram on Oct. 15 of some lightening bolts.
The couple are now the parents of two under two and their eldest daughter Taya celebrates a birthday this month.
In an interview with Hello Magazine, Spearritt and Thomas showed off their bundle of joy and shared how they are coping with parenting two young children.
"We always wanted more than one so it made sense to have another one as quickly as possible," she shared. "We have been lucky, with my mum we've had a lot of help, it's been wonderful."
In the sweet video clip, the couple shared another source of the inspiration behind their second daughter's name. "Once Taya was called Taya I think we had found our vibe and flow! [Tora] means tiger, she’s not quite living up to the name yet," laughed Spearritt.
It's a touching moment for the S Club 7 star who previously opened up about difficult pregnancies before the birth of her first child.
Speaking to OK Magazine in 2018, the 39-year-old explained how she'd miscarried twice "early on in the pregnancies."
She added: "It’s such an upsetting thing so it’s made it hard to relax this time, especially during the first few months. Going through all that makes this pregnancy even more special, though. I feel very lucky that everything has been okay this time."