My fellow Grammar Nazis, STFU.  It is intended to be a meta-pun—and I have always wanted to use her in the dative!  Also, I believe that it is correct insofar as μετᾰ has a sense governing the dative, which perfectly conveys my intended meaning.  If I be mistaken, would any pedants care to correct me?

The preposition μετά governs genitive and accusative, not dative. So your pun would work, if you wrote μετά Φρύνης.
If your priority is Φρύνη in the dative, you may forget μετά and write instead ἐν Φρύνῃ, making an ἐν-pun.