The former S Club 7 star, who is expecting her second child with husband Alex Bourne, wrapped up warm in a grey furry trimmed cape at Mothercare's VIP Christmas party.
The 35-year-old beamed as she showed off her growing baby bump to photographers, and teamed her cape with a grey mini dress, tights and black knee-high boots.
The 'Bring It All Back' singer got into baby mode and also picked up some items for her unborn baby, including some clothes from Myleene Klass' Baby K range.
At the end of the night, Rachel tweeted: "Lovely to see you @klassmyleene & thank you @mothercareuk, cute things! Couldn't resist the Baby K leopard tutu! x."
Rachel and Alex, who are already parents to two-year-old daughter Amelie, announced their happy baby news in September.
The couple, who tied the knot in a glitzy ceremony at Claridge's in London in 2009, said at the time that they were "super excited" to have a new addition to their family.
Got an iPad or iPhone? Reveal Mag has been especially designed to fit!
See who else is expecting a baby in the gallery below:
Copyright: Vimeo / Weiss Eubanks