Well, my little Uma, who is half bantam dark brahma and half bantam cochin, started laying about 2 or 3 weeks ago and has already gone broody, We gave her 5 eggs to sit on--one of her own, 3 WFBS, and one EE mutt (mom's an EE, dad's a mottled java/FBCM mix).
What's so interesting is she started laying at only 4 months of age and just turned 5 months old the other day (she was hatched in mid August). We were shocked when she started laying so young! I think she was 17 weeks old when she laid her first egg. Does anyone know if that's normal for banties?? I haven't had a lot of bantams. My porcelain d'uccle started laying at about 24 weeks and laid for a couple of months, but then her mate passed away about 3 weeks after being injured in an accicdent with a larger chicken that got the zoomies & accidentally ran him down when he was running across the yard. She laid one egg the day after Charlie passed away, and she hasn't laid an egg since--that was in September. She is just recently, the last week or so, letting our cuckoo silkie roo mate her. That might produce some funky little offspring, eh?
So we are waiting on Uma's eggs to hatch! Going to be an interesting little mix. I love broodies! It's been a couple of days & she is due to hatch her babies out on the 10th of February.
Edited for typos.
My bantams are around 5 months when they start to lay, sounds like your girl is pretty early, but am looking forward to hearing how it goes and seeing pics of course... Bantams make awesome mamas.. 
Living in the Beautiful Mountains of Western N.C.. with 16 chickens= EE's, Game, Cochin bantams,Light Brahma, 13Muscovy ducks, 1Embden Gander,1 Toulouse goose, 3 mini Dachshunds, 1 mixed breed, pond goldfish, and a wonderful Husband who makes it all possible..♥
Living in the Beautiful Mountains of Western N.C.. with 16 chickens= EE's, Game, Cochin bantams,Light Brahma, 13Muscovy ducks, 1Embden Gander,1 Toulouse goose, 3 mini Dachshunds, 1 mixed breed, pond goldfish, and a wonderful Husband who makes it all possible..♥
