Now I can't say if she had any issue with TNG's production, but there is a very good reason why she wouldn't have been considered for the Eddington role. They needed someone who could do multiple episodes. For the years in question she was rather busy. She did several films and had a series role on Homicide. That filmed on the east coast, and would have made it difficult to do another show that was shot on the West Coast without a significant work in getting clearance from Homicide's production offices.
But thee reality is Trek's casting offices wouldn't want to ask her for a recurring role. With TNG it was hard enough getting her for the episodes she worked because she wasn't a contract player (meaning they had first call on her being available). But DS9 was starting to work with far more serialized stories, and never had enough scripts int eh can to give a significant amount of notice to talent attached to other projects. Certainly by the time she got the Homicide gig in 96, that would kill almost any possibility even for a limited guest appearance. As you would need to know when she had a light work load in advance, and again I m sure neither production add scripts done that far in advance.
