As a matter of fact LOL I currently have 13 chicks that were shipped to me as eggs and raised by 4 broody hens! It worked out very well-and from reading, you have better % of hatch rate with broody hens than with incubators. (I had 31 eggs shipped , had 17 hatch, and 13 survive. Part of the problem I had was a leaky coop-first time in 3 yrs but with the record breaking rain fall its not surprising.) However, if you only have the one broody hen who has never been a mother, I would have some sort of back up ready. Of my 23 hens, in the past 2 months I have had 8 broody. I put eggs under 5 (the other 3 are recently broody) and one of the moms (banty cochin) was an excellent broody however, as the chicks started hatching, she pushed the chicks aside and only sat on the eggs. Kind of like "WTH is that???!!!!"
I just came in from my mid-morning check, of the coop. She's not yet nesting, today. But, I think that when she lays that egg, and she, being a red sex link, lays almost every day, very consistently (goes like one out of twelve days, without laying) , I'm just going to leave that egg. It might be interesting to see what happens if it hatches. A Red Comet, which is a cross (if I recall between a New Hampshire Red, and a Delaware?), then crossed with my HUGE Australorp cockerel. Could be an interesting combination.
I have another Red Comet, Who is recovering from bumblefoot surgery, that is very motherly, to my two biggest pullets. One leghorn, and one RIR. Maybe the combination of the two, might be good for bringing new little ones into the world.