EE's can be later layers, depends on what breeds they were crossed from.
Squatting is not always a purely sexual behavior, it's also a submissive behavior...sh'es submitting to you as 'head bird'.
It can happen weeks before egg appear....but it shouldn't be too long now.
New layers can be quite goofy acting, they don't know what they are doing at first and can be confused and anxious, it can take up to a month or so before they get it all figured out. Putting some fake eggs or golf balls in the nest might help show them where to lay. They may scratch around in the nests for weeks before laying. Meanwhile, eggs everywhere, some of them can be rather funky looking, soft or thin shelled, huge double yolked eggs.
Signs of onset of lay---I've found the pelvic points to be the most accurate.
Squatting:
If you touch their back they will hunker down on the ground, then shake their tail feathers when they get back up.
This shows they are sexually mature and egg laying is close at hand.
Combs and Wattles:
Plump, shiny red - usually means laying.
Shriveled, dryish looking and pale - usually means not laying.
Tho I have found that the combs and wattles can look full and red one minute then pale back out the next due to exertion or excitement, can drive ya nuts when waiting for a pullet to lay!
2 bony points on either side of vent:
Less than 2 fingertip widths apart usually means not laying.
More than 2 fingertip widths apart usually means laying.