The gods have no age.This is true... I don't think they age or anything but she was known as a beautiful young maiden so maybe in her early 20s or maybe even a little younger than that like 18 but...
Gods and Goddesses don't really have ages, as the majority of them were born before mortal time existed. Aside from that, it isn't polite to ask a lady her age ^_~
No exact age has been found regarding Persephone's age when she was abducted by Hades.Never the less, many believe that she was probably around the age of 14 to 16! That's young!