Singer recently postponed all upcoming live shows as she focuses on starting a family
Singer had been scheduled to tour the UK during March
Unbreakable tour was due to begin in Birmingham later this month
Sinher recently underwent vocal surgery
Singer urges fans to 'pray for her during this difficult time'
Singer ia under doctor's orders following illness
Dates in Salt Lake City and Denver have been pushed back
Singer says her team will 'change their approach' and allow shorter clips to remain online
Several fans claim to have received emails accusing them of copyright infringement
Pre-sales allow tickets to be purchased before going on general sale