Kelly Clarkson has hit out at a troll who suggested she put her work before her marriage.

The 'Breakaway' hitmaker recently filled in for Simon Cowell on 'America's Got Talent' after the music mogul broke his back, and a Twitter user claimed her hectic schedule, which also includes being a mentor on 'The Voice' and hosting her self-titled talk show, led to the demise of her marriage to Brandon Blackstock in June.

The fan wrote: ''now Kelly is taking Simon's place...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 (sic)''

The 38-year-old star - who has River, six, and Remington, four, with Brandon - quickly hit back at the troll for ''shaming'' her over her great work ethic.

She replied: ''Wow. Shaming a woman who has a great work ethic, is a great mom, and who steps up and fills in when a friends asks for a favor 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. Aim higher please.''

It was recently claimed that Kelly is determined her children will stay a ''priority'' following the breakdown of their parents' marriage.

A source said: ''She had to work through a lot of hurt from her childhood. Her priority is making sure her children grow up in a stable, loving environment.''

The former 'American Idol' champion is also keen to remain close to Brandon's children from a previous relationship - Savannah, 18, and Seth, 13 - whom she had been stepmother to during her marriage.

The source added: ''She's always thought of Seth and Savannah as her own too, and she has a special relationship with both of them. Kelly wants to remain close with her step-kids.''