Maia is the mother of Mercurius.
"You ask where I think the name of May comes from? Its origin's not totally clear to me. As a traveller stands unsure which way to go, Seeing the paths fan out in all directions, So I'm not sure which to accept, since it's possible To give different reasons: plenty itself confuses. You who haunt the founts of Aganippian Hippocrene, Those beloved prints of the Medusaean horse, explain! The goddesses are in conflict. Polyhymnia begins, While the others silently consider her speech. 'After the first Chaos, as soon as the three primary forms Were given to the world, all things were newly re-configured: Earth sank under its own weight, and drew down the seas, But lightness lifted the sky to the highest regions: And the sun and stars, not held back by their weight, And you, you horses of the moon, sprang high. But Earth for a long time wouldn't yield to Sky, Nor the other lights to the Sun: honours were equal. One of the common crowd of gods, would often dare To sit on the throne that you, Saturn, owned, None of the new gods took Ocean's side, And Themis was relegated to the lowest place, Until Honour, and proper Reverence, she Of the calm look, were united in a lawful bed. From them Majesty was born, she considers them Her parents, she who was noble from her day of birth." - Ovid, Fast V