Wow, that probably is a few too many for one hen. If they are sitting on eggs together odds on they will look after the babies quite happily together. You'll just have to keep an eye on them to make sure everything is going well, and check all babies are tucked up at night. With that many babies you may need to give them some additional heat. Just see how they go.
Having had chicks hatched under broodies, and buying slightly older ones that I've had to brood myself, I much prefer the chicks to have a chicken Mum. The ones my broodies hatched know how to scratch and view us as always coming with yummy treats. They will eat anything and are super friendly! I can't get the ones I'm brooding to try anything new and they are still cautious of us. And their claws are razor sharp because they don't scratch around - they just occasionally scratch in the food bowl. So much nicer to have a real Mummy.
Good luck.