The thing that convinces me is this
Kreia says the Kae is exiled due to the pregnancy, this is a lie. proof is below
Handmaiden says she remembers her father going to war for the sake of her mother, that is, the mandalorian wars, now for her to remember that she would be at least 7, probably older, so Kae at the time of the beginning of the mandalorian wars was still a jedi, yet her daughter 7 years old. if she, as claimed, died in the wars why would the jedi council declare her an exile when they found out about the daugther... that does not match.
Mical/disciple says that Revan had many masters, and mentions "master kae, until Kae went to war", so Kae was the last master Revan had before the mandalorian wars, meaning we have evidence she was still a jedi when she went to war.
Kreia says that revan returned to her for training before the end, now in Kreias view, being a greyhood now, his end would be his fall, meaning the mandalorian wars.
now remember that although kreia looks like "an old hag" the Darkside does that to people, sidious as the obvious example.
Handmaiden is most likely between 20 and 25 (aged 5-10 at the start of the mandalorian wars, add 5 years for the wars and 10 for the exile's exile)
Arren Kae, is to my knowledge never been given an age, but if you say she was in her late twenties/early thirties at the war, then add 15 and the use of DS = 80 year old looking hag.