Kelly Clarkson responds after Twitter user says her marriage 'didn't work' due to her busy schedule

American singer-songwriter Kelly Clarkson responded to a social media user who speculated on why the star's marriage to husband Brandon Blackstock came to an end.

According to Fox News, on Thursday (local time), the Twitter user began by commenting about how the 38-year-old Clarkson, is filling in for Simon Cowell on 'America's Got Talent' while the 60-year-old recovers from a back injury.

"Now Kelly is taking Simon's place," the person said before adding: "no wonder her marriage didn't work ... surprise she has time for her kids ... not the good old country girl we fell in love with ... it's all about Kelly being on tv ... and no one else ... no tears for her ... but for her kids."

Clarkson responded several hours later.

She wrote, "Wow. Shaming a woman who has a great work ethic, is a great mom, and who steps up and fills in when a friend [sic] asks for a favour because that's actually what "good old country girls" do. This can't be who you are deep down. I have more faith in your heart."

As Fox News reported, in June, the 'Because of you' singer and talk show host filed for divorce from Blackstock, according to court documents first obtained by The Blast.

Clarkson cited "irreconcilable differences" as a cause for the divorce. Meanwhile, Blackstock, like Clarkson, is also reportedly seeking joint physical and legal custody of their children.

The divorce has yet to be finalised.

The couple was together for nearly seven years and share two young children: a daughter six-year-old River, and a son, four-year-old Remington. Blackstock also has two children from a previous relationship.

( With inputs from ANI )