Kelly Clarkson absence from her talk show in the spring was due to ex-husband Brandon Blackstock's illness, sources tell PEOPLE.

A lot of questions have surrounded Kelly Clarkson over the past several months due to absences from her talk show and canceled concert dates. An unfortunate explanation came on August 7, when it was revealed that her ex-husband Brandon Blackstock died of cancer after a private three-year battle.

Clarkson and Blackstock, who was country legend Reba McEntire's stepson, first met in 2006 during a rehearsal for the Academy of Country Music Awards and reconnected years later at the Super Bowl. They married in 2013 and had two children: daughter River, 11, and son Remy, 9.