I posted this way back in the earlier pages, however as I feel it pertains to the current discussion I am sharing it once again:
Immortality should not be confused with agelessness. A person can live forever but still reflect (to a far lesser degree) the passage of time. If we are basing DC's 'immortality look' on say for instance their Kingdom Come counterparts, Superman and Wonder Woman both look 'older' than their current young selves, carrying a maturer look to them. They are not 'petrified' immortal in terms of how vampires are often portrayed.
Hippolyta was already a mature 'cavewoman' when she was granted immortality by the Gods. They did not reverse time for her but rather ****** the aging process. At present she is suppose to be roughly about 32,000 years old. Casting a 'young looking' 40s actress (and date I say early 50s actress) I feel would deliver the quality of the character that we all hope to see Hippolyta portrayed as.
Through the miracle of modern technology and brilliant make-up artists, a number of the 'older' actresses can easily look 10 years younger on film to play the part of Queen Hippolyta.