Can an 80 yer old woman look 20?

No, she can't. There are quite a few people who try to look young but are old. But they don't come off looking 20, they come off looking stupid. They come off looking like old people with a crazy fashion sense. An 80 year old woman will have wrinkles, skin discoloration, saggy skin, not a hot body. So wearing clothes that younger people wear won't make her look younger, it will make her look crazy.