Our situations are SO similar - except I have twice the eggs and both broodies are first-timers...
Actually I believe this is the first time hatching out chicks for the 4 year old broody too. When I went to pick her up at the breeders place I saw chicks in brooders but none with hens (they were not in large pens, but kept in smaller wood cages that were obviously custom built) so I think they incubate the eggs artificially.
I have 6 dogs and 5 are okay, but the 6th is an older hunting Coonhound (showed up here 2 years ago). He goes freaking INSANE over chicks in the house which is one big reason I love the idea of having the chicks raised by broodies, he doesn't care about the chickens in the pen outside but if they are inside the house he is unbearable (and untrainable).
So glad we can have a hatch a long this weekend! Or maybe even Friday as all of mine are bantam eggs too!