It wouldn’t be the first time the show killed off a beloved character. Or, really, the first time, a child’s death happened. Early in the series, we see Carol lose her daughter, Sophia, when Carol is reunited with her, it’s revealed that little Sophia is now a walker.
So The Walking Dead isn’t above killing off kids, as much as we hate it. It’s still hard to believe that Judith’s plot armor isn’t thick enough to protect her until the series finale, though.