The singer, who co-founded the band with Keisha Buchanan and Siobhan Donaghy, admits that she can't be "bothered" to argue with the band, and is focusing her efforts instead on becoming a child psychologist.
"I took up a course in child psychology because it was an interest of mine," she told the Daily Star.
"I can’t be bothered to argue about the Sugababes, it’s so silly. I’m in two minds about music in general. I love doing it but I’m not sure if I want to carry on."
Discussing George Michael, who was recently released from prison and with whom Buena once collaborated with on 'This Is Not Real Love', she said: "Bless George. He is having a hard time. He only gets caught for these things because he gets followed constantly.
"I’m enjoying being out of the spotlight, not having people follow me on motorbikes."
Last month the 'Real Girl' star released a Sound Of Camden LP, featuring cover versions of songs by the Rolling Stones and Nirvana.