Buena said that it would be "amazing" to reteam with her old bandmates Siobhán Donaghy and Keisha Buchanan in the future.
"Well you know, we're all grown up. I haven't been with the Sugababes for so long, and you know, I've had my years of growing up and learning about what I want in life and getting to look after my daughter," she told GMTV.
"So hooking up with the rest of the girls - I think that could be an amazing idea, definitely."
Buchanan, who was the only original member of the girl group, confirmed that she had split from the band earlier this week. She has been replaced by British Eurovision star Jade Ewen.
Commenting on the new lineup, Buena said: "Personally, I just don't think the Sugababes is the Sugababes anymore. I mean, it would be different if Keisha had stayed in it and someone else had gone - then it would be the Sugababes. But wow, I suppose now there's no original Sugababes we should just all reform again."
Buena left Sugababes four years ago, while Donaghy quit in 2001. They were replaced by Amelle Berrabah and Heidi Range respectively.