"Okay if @laporsharenae doesn't win Idol there's something seriously wrong w/America!" she tweeted. "I mean, goodness! I stood up in my house, that's right!"
Renae -- clearly shocked by Clarkson's support -- shared her excitement on the micro-blogging website.
"OH MY GOSH!! THANK YOU SO MUCH!! Such an honor!!!! Wow....#IdolTop24" she wrote.
The single mom received praise from the judges after her performance, particularly from Jennifer Lopez who said, "It's a joy to listen to you sing. I just love it. Voices like yours, I swear I dream about them."
Kelly Clarkson, More Alumni to Return to 'American Idol'
Clarkson will return to the Fox singing competition as a judge on Feb. 25.