At the moment I can only think of expressions like:
a woman who's over the hill
a women no longer in her prime
a woman who's past her prime
Then there's the more positive way of looking at it:
a delightfully mature and sophisticated lady
P.S. You'll be entirely unsurprised
Sadly, and contrary to the expectations I had in my younger days, I am never completely surprised when people demean women - anywhere in the world.
Thank you for your comments by the way. I had looked at the Redensarten website prior to posting yesterday. I have no idea how reliable the information there is (if you're familiar with the site http://www.redensarten-index.de/suche.php
perhaps you could comment on that), but the author of the alte Schachtel article seemed to think that unpleasantness was one of the characteristics.