There are many legends regarding Ariadne in Greek mythology although it seems Ariadne was a princess of Crete. She was a daughter of King Minos and his Queen, Pasiphaë, and the legacy of the god Zeus (on her father’s side) and the titan Helios (on her mother’s side). She is most commonly known for helping the Greek demigod hero Theseus get through the Labyrinth in Ancient Greece. She became the immortal wife of the god Dionysus after Theseus abandoned her. Her Roman counterpart is Ariana. Reference: Fandom
Ariadne fell in love with the Athenian hero Theseus and, with a thread or glittering jewels, helped him escape the Labyrinth after he slew the Minotaur, a beast half bull and half man that Minos kept in the Labyrinth. Here the legends diverge: she was abandoned by Theseus and hanged herself; or, Theseus carried her to Naxos and left her there to die, and she was rescued by and married the god Dionysus. Reference: Encyclopaedia Britannica
In cameos and other art, Ariadne is often portrayed with her husband Dionysus. This can be either as the figure of Dionysus or by symbolism. The symbolism can be a panther, either together in sometimes portrayed with a panther. Panthers were the preferred mount of Dionysus so this is often portrayed with Ariadne. Also, ivy was associated with Dionysus so Ariadne is often portrayed wearing an ivy wreath. Sometimes she is depicted sleeping which probably relates to the legend of Theseus leaving abandoning her while she is sleeping on the shore of Naxos.