I've read some chickens can lay anytime between 5-6 months...so could they lay in January?
People keep looking for absolutes. Sorry but you don't get that with chickens or really any other living animal. They can lay between 5 or 6 months. Occasionally you can get one to lay after 4 months, but don't expect that this time of the year. I've had some not lay until 9 months. It's possible you could get some in January, I would not be shocked with your breeds. But I also would not be shocked if it were March before you get eggs.
Because they came from the same mom, would they both lay the same color or is it random?
It can be random, especially if they are EE's. The mother and father both contribute genetics for shell color. Depending in what genetics each contribute you can get different colors and different shades, even if both pullets have the same mother and father.
I keep telling my family they are Easter Eggers but they are soooo sure they are Ameraucaunas
The APA recognizes eight varieties of Ameraucana, either bantam or full sized.. They are black, blue, blue wheaten, brown red, buff, silver, wheaten, and white. If those were true Ameraucana the feed mill would have told you which varieties they were. So yes, probably EE's. Still, they will be a lot of fun.