According to wikipedia and SongFacts.
http://www.songfacts.com/detail.php?id=41384

She isn't credited on youtube or spotify though unfortunately, but it's good to see her making a success of herself! Apparently she's been busy as a songwriter.
https://en.wikipedia.org/wiki/Laura_White

She was in the same year as Alexandra Burke, JLS and Ruth Lorenzo and was knocked out against Ruth in the singoff one controversial week.

I think her vocal is pitched up a bit (which explains the lack of credit). I think she's recently signed a contract to write songs.