This is getting ridiculous. The light from her clock is constantly broadcasting her current age. That light could reach his eyes (with aid of a powerful telescope), and just before he stopped, it would show her clock displaying 16.91 YEARS. Once he stops, he will still be able to use his telescope to look at the flow of light coming from her clock. If his stopping takes a fraction of a second, he will see her clock displaying 16.91 years plus a fraction of a second. It makes no difference, and the fact that you are going down this path of argument makes me wonder if you even understand anything I am saying. So he stops moving, and sees her clock saying 16.91 years (plus a fraction of a second!), knowing that the distance between them is 23.09, and calculates her age to be 16.91+23.09=40.000. You are arguing that he can't do that, because he calculated a different value a fraction of a second earlier? Just the fact that your end result has non-constant speed of light should be an immediate sign that you are wrong. But if you think this is just a new way of doing SR, I will leave you to your delusions.