Ps.-Plutarch, Parallela minora 19A, 310B-C
“Kuanippos, a Syracusan by birth, did not sacrifice to Dionysus alone. In rage over this, the god caused him to become drunk and then he raped his daughter Kuanê in some shadowy place. She took his ring and gave it to her nurse as to be proof of what had happened in the future.
When they were later struck by a plague and Pythian Apollo said that they had to sacrifice the impious person to the Gods-who-Protect, everyone else was uncertain about the oracle. Kuanê understood it. She grabbed her father by the hair and sacrificed herself over him once she’d butchered him on the altar.
That’s the story Dositheos tells in the third book of his Sicilian Tales.”
Κυάνιππος γένει Συρακούσιος μόνωι Διονύσωι οὐκ ἔθυεν· ὁ δὲ θεὸς ὀργισθεὶς μέθην ἐνέσκηψε, καὶ ἐν τόπωι σκοτεινῶι τὴν θυγατέρα ἐβιάσατο Κυάνην· ἡ δὲ τὸν δακτύλιον περιελομένη ἔδωκε τῆι τροφῶι ἐσόμενον ἀναγνώρισμα. λοιμωξάντων δὲ, καὶ τοῦ Πυθίου εἰπόντος μὲν δεῖν τὸν ἀσεβῆ <᾽Απο>τροπαίοις θεοῖς σφαγιάσαι, τῶν δ᾽ ἄλλων ἀγνοούντων τὸν χρησμόν, γνοῦσα ἡ Κυάνη καὶ ἐπιλαβομένη τῶν τριχῶν εἷλκε, καὶ αὐτὴ κατασφάξασα τὸν πατέρα ἑαυτὴν ἐπέσφαξε, καθάπερ Δοσίθεος ἐν τῶι τρίτωι Σικελικῶν.