Kelly Clarkson isn't here for the rude commentary! The 38-year-old musician and TV personality took to Twitter on Thursday to respond to an online troll who insulted her decision to step in and temporarily replace Simon Cowell on amid the British judge's recent back injury. «Now Kelly is taking Simon’s place ...no wonder her marriage didn't work...surprise she has time for her kids,» the tweeter wrote in a since-deleted tweet.