She will be able to hatch them. I have one quite tame hen who always goes broody early.
One year the weather turned bad so I moved her inside and into my brooder with the heat lamp at the other end. She sat tight for another couple of days so I gave her the chicks (I try to have the incubator going with eggs for when I get a broody - hen can hatch a dozen well but can brood twice that). Within a week the weather was beautiful and the whole lot were out in the sunshine.
People decide they want point of lay pullets in June/July so I think it's handy to have some hatched out early and ready to go to their new homes.
But if you don't at least have a shed that you can move her coop and run into, I probably wouldn't risk it.