Lord Elrond could see her hesitation in telling Kili and Yavanna the truth about her past. He knew how much his daughter had hated lies; so this would not be a good mark in Saeril's books, if it upsets his daughter. "Yes, they will have to know." he said in agreement. "It's up to you, if you'll like to say the truth yourself at the meeting...or myself or Gandalf can explain it ourselves." he offered for her.