It was not up to Megyn Kelly to defend Rosie O'Donnel. It was her place to ask questions and let the candidate reply. She did challenge Trump's statement that it was only Rosie that he defamed. Unlike Candy Crowley, she did not try to interject herself into the debate even though Trump tried to pull her into it.
I think BumsN means that kids aren't safe left in cars, either. Which is true. Picture someone stealing a kid left inside a car...and if they get caught...they could just use the excuse that they were "...just saving the little child from heat/cold...".