I'd keep the prolapsed tissue coated with ointment or oil so it doesn't dry out. You can try pushing it back in to see if she retains it, but it may come back out when she poops. Hard to know.
Continue with the Calcium daily for at least 7 days.
She can eat her normal feed and she also needs to be drinking/staying hydrated.
I'd watch carefully that flies don't get on the tissue or that other hens don't pick at her if you have her outside.
For the comb, it may be Fowl Pox. You can paint the lesion(s) with Iodine to help dry them up.