When will they start laying?

[_ss233]

My oldest three hens are 19 weeks old. My olive egger sure looks close to laying her first egg based off her comb and waddles but I’m new to this and wondering how long it may be? Can they be this developed for weeks before laying?

 

[rosemarythyme]

That's a pretty red comb, so "sooner" rather than later. Other signs to look for are pullets messing around in the nest boxes and squatting if you reach down towards them.