What is the symbol of eternal beauty?
The rose is the symbol of eternal beauty.
i only know the Egyptian symbol of life which is the ankh. - Ankh is both the symbol of life AND death as the ancient egyptians saw life and death as mirrored. So ANKH = Life, death, eternal life, Pharaoh's key to eternal life. You can learn a lot here: http://www.touregypt.net/featurestories/ankh.htm
Gods had symbols. Helen was human (or, at best, a demi-goddess) and everybody praised her beauty, which cannot be called a symbol. Her beauty was her symbol. She did not have a symbol like Zeus had his lightning bolt. This is because she is only a demi godess. Her father, Zeus, was a God, but her mother, Leda, was a mortal.