It's tough without seeing them in person (both the hen and the egg, I mean). My assumption at this point, though, would be that she's mostly Leghorn with white Rock introduced into the line at some point in the past. Her comb is really small for a Leghorn and her egg should not be tinted if she was pure, but she does have the general shape... I guess it doesn't matter too much unless you planned to show her. She is lovely, either way.