Talk:Gorgon/@comment-24495865-20170917162815/@comment-31096423-20170918020933

I'll try to clarify their relationship, not directly answering your question, but giving you information so you can reach your own conclusions.

The three Gorgon sisters are Medusa, Euryale and Stheno, Medusa being the youngest, and Stheno the eldest of the three.

Although they were all born from the same parents, the gods Phorcys and the goddess Ceto, only Medusa was not given inmortality, and thus, she grew older as time passed. She was also jealous of both of her sister's eternal youth, something which, in time, made her descend into the path of madness some time after being cursed by Athena after having intimate relations in one of her temples with Poseidon (actually being raped...). She was then exiled into an island where both her sisters attended to her needs, but after some time she went completely mad and finally ate both of her sisters, eventually becoming the mythical beast Gorgon.

Summing up, Medusa, Euryale and Stheno are sisters, Medusa turned into Gorgon after eating both of her sisters, Medusa also used to be young since she was not immortal (known as Ana in Fate/GO, or Medusa (Lancer))