Did she still sleep with the chicks and night and hang with them most the day?I've only let one broody hatch eggs but around week three she started leaving the chicks to lay an egg. I only have three blue layers and she's one of them, and I was regularly getting three blue eggs in the nesting box. Maybe she is an odd ball?
I've had 3-4 they never laid until after weaning the chicks...
....but that's why I said 'usually'. Ya just never know with live animals.