Quote: The short answer is that your very pretty EE pullet will likely lay brown eggs, but you won't know for sure until she does.
Here's why:
In Ameraucanas (and Arraucanas), the gene for pea comb lies very close to the gene for blue eggs. Due to their proximity, the genes usually travel together during reproduction, so if a chicken of this ancestry has a pea comb, it is very likely (but not absolute) that the chicken will also carry the gene for blue eggs. Muffs/beards and blue legs are also Ameraucana traits, and may help determine ancestry, but they are not connected to the blue egg gene.
Since EEs can have other breeds in their background, new genes and different outcomes can occur, including mixed type combs. The outcomes are not as predictable as in purebred birds. To confuse matters more, other breeds have pea combs but do not carry the blue egg gene, and there are some single combed birds that do lay blue eggs (Cream Legbars and a breed developed at the University of Arkansas that crossed blue Araucanas with Leghorns). Adding these breed types into the mix will make predictions even harder.