I'd email the breeder and ask what breeds are in their sex links. Sex links can be a cross of pretty much any breed, as long as the hen is barred. For example, a black rooster over a legbar hen would give black sexlink pullets that have a crest. Cuckoo silkies or barred polish could also give a crest. Or maybe she's not a F1 cross, a barred olive egger bred to a solid rooster could also give you black sexlinks.
Thank you for both of your suggestions. As I have been looking up Easter Eggers and what some breeders use for breeding these birds. I took one of your suggestions and went to the original breeders website. They use Americauna Roosters, and after having Cream Legbars myself which are very unique with the tufts on their head. I am assuming that is what this girl is an Americauna/Legbar cross. It will sure be fun to watch her grow. Thanks again!