The new parents looked happy and relaxed outside the Sanderson Hotel in central London on Tuesday evening (20 August).
Earlier in the night the pair had walked the red carpet at the This Is Us world premiere in Leicester Square, where thousands of fans had camped for days in a bid to catch a glimpse of their 1D idols.
The Saturdays star Rochelle looked gorgeous in a Dolce and Gabbana dress, teamed with a Swarovski necklace, while Marvin looked as dapper as always in his suit.
On arriving at the premiere, the JLS star tweeted: "Leicester Sq madness! Big congrats to all the @OneDirection fellas! Looking forward to seeing the movie!!"
He joined up with JLS band mates Aston Merrygold and Oritse Williams inside.
Rochelle and Marvin left their daughter Alaia-Mai (born 20 May 2013) at home for the night, but no doubt Rochelle was checking in every hour.
She told us at Virgin Media's V Festival last weekend she felt "sick" leaving her daughter at home overnight while she performed at the two-day event, adding she'd been checking in with her babysitter mum all day.
"That baby is just everything in my life, I want to go home really," she told us.
Watch a trailer for This Is Us below:
Rochelle isn't the only new celeb mum. Check out more star arrivals in our gallery below:
Copyright: Love & Lust London