The 'Born This Way' singer took to her Facebook page Saturday to defend her statements in response to Kelly's mother Sharon Osbourne's comments that Gaga was "bullying" her daughter, reported Us magazine.

"The 'real world' can be cruel, why not try to change it into a better place? I am an activist. Nobody takes adolescents seriously, I do. My letter to Kelly Osbourne was open, because her statements on cyber-bullying were public & as a youth activist I'm compelled to be involved," Gaga posted.

On January 10, Sharon took Gaga to task in a scathing note on her Facebook page, telling the 26-year-old singer to stop being self-righteous while engaging in hypocritical bullying behaviour herself.

"You say [Kelly's] work on E! with the Fashion Police is 'rooted in criticism, judgement, and rating people's beauty against one another.' Welcome to the real world," the 60-year-old talk show host said.