how do I as a 56 year old 5'2 chubby built average looking gal get into prom?

Are there any blind schools around your location?

Why yes, there is.

Are you saying maybe one of the students at the school would like to give me their prom dress?

It's worth a try. There's also the School for the Deaf I could hit up.

You might dress as a chaperone and come in through the side door.