Ed Sheeran is also on the bill for May 17 ceremony
Singer collects two gongs from the Las Vegas Review Journal
Comment appeared to follow an audience member calling her a "fat bitch"
'Pretty Girls' is a collaboration with Iggy Azalea and Little Mix
Singer also sets US release date for forthcoming Iggy Azelea collaboration
'Pretty Girls' will be produced by The Invisible Men
Singer is concentrating on motherhood as she is embroiled in fresh legal dispute
Spears has two children with former dancer
Spears' vocals were a warm-up exercise, says William Orbit
Midweek chart update also reveals Lily Allen is on course to return to Number One in Singles Chart
The popstar was spotted wearing a Virginia Tech hoodie and then brandishing a gun
Producer worked on track for US star's forthcoming studio album 'Britney Jean'
Preview of show to be held in New York on November 7
Navy officers play songs including '...Baby One More Time' to ward off criminals on the high seas
The pop star will release her eighth LP on December 3
Actor tweets pop star following claims she did not like final episode "at all"
Larry Rudolph also gives update on singer's new album
Former Swedish House Mafia producer was believed to have worked on popstar's new single
The track, taken from her forthcoming eighth studio album, was due for release tomorrow (September 16)
'Toxic' singer has also had sessions with a choreographer