Okay, I really liked this story. Really.
But it had one flaw that, while very minor, seriously dragged me out of the story.
Ena met Jax at the age of 19, when she was just starting her career. Then after twenty years of working she is too old and worn out to be of use to the employers. Let me do the math... 19 + 20 = 39!!
Really? Someone is too old and decrepit at 39 to work? Ummm, retirement age in the western world is around 65. So what do people do for the remaining 26 years of their working life?
If there was some reason for Ena to be unsuitable for work at age 39, this should have been clearly spelled out in the story, because in the absence of other information, you would expect Ena to be a normal human, comparable to us, and therefore able to work well into her 60's.
I know this is a minor point in the story, but it really pulled me out and lessened my enjoyment of this otherwise very interesting story. And it dragged me away from commenting about more pertinent things, like how well this story addressed the satisfaction that can be had from a close and life-long friendship.