I can't believe you're the one asking. I'll answer you like I would anyone else. You'll know the answer when you see an egg.
There are several clues that they are getting close. Pelvic spread, vents damp or dry, bright red combs and wattles. But these are all clues that they might possible be getting close, not guarantees. I consider the damp versus dry vent the best.
Squatting is another clue that they might possibly be getting close. I consider it a good sign. But I once saw a 13 week old pullet willingly squat for a 13 week old cockerel. No force, intimidation, anything. He signaled and she squatted. They went through the entire process, including vent touching. It was two months before she started laying.
I don't know under what circumstances you are seeing squatting, anything like that. It is frustrating to wait, I've been there. When I hatched eggs to get some blue and green egg layers it took them nine moths before I saw the first egg out of three pullets. Nine months, in the middle of December. Then two were laying within a couple of days. I don't know when they started squatting but nine months!
I can't remember how old yours are, you've probably mentioned it in another post somewhere. Just hang in there. I really don't expect you to have to wait much longer. Sure wish you luck!