First time trying to hatch

[Mumite]

We have three hens, one faverolle, one brahma, one rescue and a rooster plus three ducks, of which one at least definitely female as she started laying eggs last week, they are only just mature.
We introduced a leghorn rooster about two weeks ago and he was often seen with the faverolle, anyway a few days ago (I think three) she went broody under the hedge and so I've moved her to a small dog kennel with the eggs. We broke open a few eggs and saw the "bullseye" in the other hens' eggs too and apparently in the duck eggs so we are putting eggs laid underneath the faverolle until she has a good few there (currently 5 i think). The rooster sat with her in the kennel overnight and has been checking on her regularly and guarding her, as I do leave the door open for her to free range but she has only been out once very quickly today for food. I'm a bit worried about all the eggs hatching on different days given we are slowly adding them day by day, and i also worry about where to keep the chicks for first few days as I've no spare run though I do have a large dog crate I could maybe wrap in chicken wire. Any suggestions and any other tips please?

She won't abandon her chicks, but stop adding more eggs- a small clutch is best at first. Do isolate her and her brood if you can. She will probably leave the nest for about an hour a day to feed and drink. She isn't likely to abandon her brood once they start hatching and the chicks will follow her around fairly quickly, but they are vulnerable to predators and other chickens.
Breaking open the eggs to test for fertility is a little wasteful- you could candle them (shine a strong light through them, great fun at intervals to see the embryo developing) and not have wasted the eggs.
Get some chick crumbs in to feed them. If you hatch duck eggs as well, get coccidiostat-free crumbs for them.

Thanks Zippy, will check out the two kinds of chick crumbs and must try candling - we didn't want to waste the eggs but didn't know you could take them from under the hen to candle. She is sitting really well, comes out for morning feed and huge drink and poop only, then back in, as there is a large door on the dog kennel she is in I then shut her in as the other chickens and even magpies are a threat otherwise. The cockrel must have tried to mate or approach today when she came out for morning feed as they had a big fight, she was abit disorientated when I broke it up and so I put her back on the nest, i think she was still in "guard" mode but back in the dark she settled quickly. It is exciting (excuse the pun!) and marvellous but a bit nerve-racking too.