When will my broiler start laying?

[farmer4]

ignore my rooster on the right. They are 15 weeks old and my hen is as big as my rooster. I know broilers aren't good laying chickens but I have 4 more of them.

 

[Wyandottes7]

If your hen lives (very few broiler hens do, as they get too big), she should start laying at about 5-6 months old.