I love the pic of your BO and her brood!
If she's anything like my latest broody, a six-year old Speckled Sussex named Linda, she could dote on those little twerps for weeks to come.
Linda weaned her one surviving early summer chick at five weeks. Then 40 days later, she incubated and brooded two more chicks. She tried to wean them a few weeks ago at just around fifteen weeks. She was half-hearted in her attempts to force a separation. Actually, all she did was move out of the coop, effectively abandoning her nearly full-grown chicks.
I praised her and congratulated her at finally cutting the apron strings, and.....well, next night she moved back in. She's still with them, a pullet and cockerel, Trixie and Toots, respectively, at age 18 weeks. She still permits them to associate with her, they do everything together, all inseparable. How long this will last is anyone's guess. The only certain thing about broodies is they are unpredictable.