Oh, for goodness sake!
First of all, they were both 15. Second, after leaving the game alone for a couple of days, I just started it up to check their ages. Their potentials have returned to what they should be.
Something new had been added — there were two Week 48 saves, the second being from when I was running through the old weeks to see if they were all 'corrupt' (or whatever the problem was). Its time stamp was about 14 hours after the other Week 48. When I hit 'resume current game' it sent me to this 'new' week 48, and all of the weeks are now uncorrupted. The two Week 48s were slightly different, but very close (probably something I did when checking them).
I have now deleted all of the old saves except Week 50. (Unless my shutting the game down just generated another one?) Anyway, today or tomorrow I will try playing and see if anything new has happened.
This is probably a bad place to put this, but here is another suggestion for 1.0c or 2.0: During creation of the default character, one of the things you can do is change her height. A text appears that says something like tall players are potentially stronger, but short players may be faster. When I first noticed this a couple of weeks ago, I tried making Emily as tall as possible, and as short as possible. I saw no differences in her potentials. I think it would be a good thing if there was a difference, something on the order of a 1% increase in strength potential and 1% decrease in acceleration potential for each cm above the default, and the reverse for each cm below the default.
Tall people really have no disadvantage in speed (witness basketball players and track runners), but if height is being used as a proxy for muscle mass, taller (more muscular) players might well not be able to accelerate or change direction as quickly.
Just a thought. It is also possible that you have already incorporated this, and for some reason my test did not pick it up. I would try again, but I am not starting any more new games until 1.0c is released.