The girl group were formed on Popstars The Rivals back in 2002 and were one of the first - and even to this date, very few - success stories from such reality shows.
They parted ways after more than a decade together in 2013 and this year celebrate their 15th anniversary.
On a possible comeback, Sarah wasn't sure.
"I don't know. It would be a group decision, so you'd have to ask as a whole, not just me," she said. "I love reminiscing and looking at our old tour footage because we were in a bubble.
"Touring for me was probably one of my favourite parts of being in Girls Aloud. Not the rehearsals, mind - but getting out here, meeting fans and performing. That's why I do what I do."
She added: "I didn't do it for the game, I did it because I genuinely love performing, singing and entertaining. It's all I've wanted to do since I was a little girl."
In tonight's episode of CBB, Sarah reflects on her time in Girls Aloud while chatting to Amelia Lily who supported the group on their final tour.
Sarah tells Amelia, “you must have only been 18 when you came on tour with us.”
Amelia goes onto say, “If I could relive anything in my career, it would be your tour. I had the best time.”
Sam asks Sarah what her top moment was when Girls Aloud were at the height of their fame and she reveals, “Probably the Brit Awards. But then when we met the Queen as well at the Royal Variety. I’ve got one more, at Wembley Stadium supporting Jay Z and Coldplay.”
Speaking about Chris Martin, Sarah tells them “he always said he’d like to write us a song back in the early days.”
Sarah previously discussed her 'feud' with Cheryl on the show as well.
Asked if they fell out, Sarah said: "Everyone asks that. It's just that we’re so busy with our own stuff... It’s not for me to say, honestly.
"I don’t like talking about the other girls”, she replied when fellow housemate Jemma Lucy asked if they are still friends. "We were like sisters, so it was never going to be plain sailing the whole time.
"I've been around girls all the time, it's difficult sometimes.
"Nothing's forever. We went through a lot together, nothing lasts forever, we went through so much.
"Even if we had fallen out I'm sure it wouldn't be a major deal in the future."