To find, in Fr. Rothers beatification, cause to wonder whether there's sexism behind it is to be obsessed with sexism.  That kind of obsession is self-oppressive.  Be free.  Save your feminism for real concerns, such as provable discriminatory hiring or provable pay disparities, and the like.  

No, I don;t know why it's taken so long for the nuns to be beatified.  Nor do I know why it's taken other male martyrs so long.  You haven't a scintilla of evidence that it's sexist, yet you raise the issue here in a wonderful article about Fr. Rother.  Question your own maturity first.