Hi Suep
The hen needs to come off the eggs at least once a day to go poop, eat and drink. If she isn't doing this herself then you will need to lift her off
You may then need to take her back to her eggs if she isn't used to the new house
Eggs usually take 21 days to hatch and some have been known to come out at day 23 so leave her for a good day or two
As for the puppy pen for the chicks it depends on the size of the holes, chicks are small and can wriggle out of the smallest hole, leaving them vulnerable to predators
Has the pen got a roof to stop magpies and the like getting in?
Mum knows best as to the weather she will gather them under her if she thinks it's too cold, an area for her to shelter under is advisable though
Lastly have you got all the other bits needed for chicks? Small shallow drinker, they can fall in deep dishes
Also have you found a place where you can buy chick crumbs?
Sarah