Lots of discussion since I last checked the forum!!
As to my original question - the hens did sort it out themselves. I had the two hens side by side in nesting boxes, the one on eggs and the other had no eggs but was persisting in being broody (5 weeks!). So, three chicks hatched (disappointing). And I had built an extension (covered) on the front of the nesting box of that hen, so the chicks wouldn't fall out and no one could go in an steal them. Well, I forgot that the back was open. So, the day after they hatched, I walked into the coop and found the 5 week broody hen on the ground, guarding a chick!! I guess the chick must have fallen out and this broody saw her chance. So I put the broody in the nest with the newly adopted chick and watched. The chick was peeping at first, and mom pecked at her almost desperately, as if to get her to hush, "don't say anything". The original mom looked a little perturbed but didn't get excited. After a while, I put the two moms in separate crates, the original mom with two chicks and the adopting mom with the one chick. This morning, I opened the crates, after shooing everyone else out of the coop. The hens and chicks came out and I kept an eye on them. There was a scuffle at one point where it looked like they might both have been wanting the one chick, but the original mom backed off. The adopted mom is trying very hard to get her chick to stay with her, and the chick does stay close, but this mom seems to not have the knack for getting the chick to tuck under her. She pecks at it a lot, even knocking the chick over at times, and the chick tries to get under the mom, but the mom doesn't lift her wing and tuck like they usually do. So, I feel kinda sorry for the adopted chick. It might have been better off with the original mom. But, hopefully they'll all play together over time...