Maybe a combination...
Her chronological age, and her bad comic jokes "My brother is so gay that he...", and something possibly unlisted but which she-hopes-won't-be remembered in cliquish Hollywood probably ired her.
But, it's probably time that for some professions, there be two additional questions:
-- Age you THINK you appear or can pass off as
-- Age OTHERS think you appear to be
But, maybe this is just me, i cannot STAND to watch shows in which actors over their age try to pass themselves off as younger types of characters. Usually, I can spot it in the body language and if the camera reveals too much in the face. I get turned off and will quit watchnig. To me, some acting is about looks, looking the part, being recruited for it due to versatility, and getting out of the way for new replacements who *earn* their way there, not retain it due to connections.
Not that that is how she landed roles, but maybe she should diversify her acting portfolio or do smaller projects that gradually mature her persona on screen. Turning silver before the silver screen isn't bad. The bad part is being typecast for so long that roles are not even offered.
Besides, it doesn't take IMDB to out her age. Agents and industry players who schmooze and booze it up can and already DO do such outing. She should probably specialize in hiring or retaining someone who writes scripts around HER and a small cast, and puts them to digital camera, and "floats" them out there on YouTube and other outlets. It would keep her active, keep her in the minds of the right people, and work better than firing a broadside via lawsuit.
The lawsuit action i dare say probably has gotten her blacklisted by now. Lots of connections all over the place...