Yes if they have pipped into the air cell you should see that, I was lucky enough once to catch this. Just make sure to put the eggs back the same side up you found it.
And yes put any foster chicks under the broody before she leaves the nest, but being a first time mama she might be slow coming off the nest. My first time mama is 5 days now and I had to haul her off she was getting a bit depressed I felt. Normally they will come off the nest around day 4 though I have found. Not sure if you can get chicks still were you are. but it's not the end of the world if she only raises one chick, there is a person on here who has one chick being raised by 5 (yes 5!) broody silkies. That chick is doing very well!