Singer had been rumoured to be making live return at 2015 festival
Photo was uploaded by star to her Instagram account yesterday (January 22)
The follow-up to 2011's '21' is mooted for release later this year
Singer is understood to have "made a donation" to charity in lieu of recording vocals for the single
Chris Martin, Ed Sheeran and One Direction all performing on the charity single
The singer is alleged to have not replied to Collins' interest in a collaboration
The singer's record label say 'There will not be a further new release by Adele during 2014'
Singer sued picture agency over photos of one-year-old Angelo Adkins taken in a playground
Martin Mills of Beggars Group says there is "no truth" in speculation
OneRepublic's Ryan Tedder and Phil Collins have both claimed they are writing with the singer