Pretty impossible to know what breeds behind a hatchery EE especially without photos of the actual bird. "Looks like this" isn't the same as a real photo...if you notice the birds in all the photos have different leg colors.
If there is beard and muff, then Ameraucana was fairly close back as those drop out pretty quickly.
If it is not a solid black or a solid white, then likely not closely related to either Australorp or White Leghorn as black and white base colors are pretty dominant.
But that leaves a long list of possibilities with red tone birds like RIR and RSL (however you usually get a lot of base red with those) and a whole list of possibilities with partridge types, brown types, mahogany types, and buff types....and that's not counting for if an EE was used as a parent (which is likely) who can completely skew results as well.
So to create a list of suggestions, it is easiest when you have a list of possible real parents. Then genetic statistical probabilities can factor in.
What I can say is look at the beard/muffs and the comb. If it is pea comb, then likely you'll get some blue or green eggs as likely the blue shell gene passed too. If you get clear blue eggs, it is likely some white layers were close back as the genes for brown wash didn't present ahead...which they usually do even in some tone if one of the parents is a brown layer type.
All that can be said without more information of the actual parentage. You can also look up the hatchery and see what birds they carry. That can help you figure out what might be behind them...but hatcheries will work on their EE lines for a long time, so there can be many, many genes represented.
Hopefully they will lay lovely green eggs for you soon. (Then you'll know you've got some brown layers close back
LofMc
If there is beard and muff, then Ameraucana was fairly close back as those drop out pretty quickly.
If it is not a solid black or a solid white, then likely not closely related to either Australorp or White Leghorn as black and white base colors are pretty dominant.
But that leaves a long list of possibilities with red tone birds like RIR and RSL (however you usually get a lot of base red with those) and a whole list of possibilities with partridge types, brown types, mahogany types, and buff types....and that's not counting for if an EE was used as a parent (which is likely) who can completely skew results as well.
So to create a list of suggestions, it is easiest when you have a list of possible real parents. Then genetic statistical probabilities can factor in.
What I can say is look at the beard/muffs and the comb. If it is pea comb, then likely you'll get some blue or green eggs as likely the blue shell gene passed too. If you get clear blue eggs, it is likely some white layers were close back as the genes for brown wash didn't present ahead...which they usually do even in some tone if one of the parents is a brown layer type.
All that can be said without more information of the actual parentage. You can also look up the hatchery and see what birds they carry. That can help you figure out what might be behind them...but hatcheries will work on their EE lines for a long time, so there can be many, many genes represented.
Hopefully they will lay lovely green eggs for you soon. (Then you'll know you've got some brown layers close back

LofMc