The one-time X Factor contestant didn't make the cut for the final of the talent show competition.
She was put together with two other girl singers to make up Belle Amie.
But the girls failed to get off the ground with their first single and the cracks began to show at the end of last year.
Rebecca (22) finally quit Belle Amie at the beginning of April, leaving remaining members Esther Campbell and Sophia Wardman to explain the situation.
"We're really sorry to announce that Rebecca has decided to leave the group to pursue a solo career," they said.
"We're really upset with the decision made as the future for Belle Amie was looking bright."
Now Tallaght native Rebecca has moved on to collaborate with up-and-coming Irish rap star Rob Kelly.
Rebecca's vocals appear on the rapper's latest single The Real Thing, which was just released this week.
Rob, from Wexford, is coming into his own and has been tipped for success by rap heavyweights Tinchy Stryder and Ruff Sqwad.
And Rebecca has transformed her quirky pop style and dyed her trademark short locks a bright blonde, similar to megastar Rihanna.
Belle Amie had been plagued with rumours of infighting and simply failed to capture the public's imagination the way Little Mix did the following year.
The big success story of 2010, which was the year Rebecca entered, were superstars One Direction.
The five-piece boy band have soared to meteoric levels in Europe and even in the US and Australia.
Rebecca earlier explained to the Herald how she was disillusioned by the lack of support for her band's single Girls Up in Ireland.
"I was really disappointed with the radio stations at home when we released Girls Up. For some reason there wasn't that much support for us here in Ireland," she said.
"I know that my friends and family were texting and calling all the radio stations requesting the song to be played but no one would play it."
Rebecca said that the frustration made her turn to mixing tracks and exploring new genres of music.