Daughter of Zeus and Leto. Twin sister of Apollo.
Zeus.
Zeus was a god. Known as the King of Gods and wielder of the mighty thunderbolt, he lived atop Mt. Olympus with his wife, Hera, amongst the many other divinities. Regardless of his wife (also his sister), Zeus had a tendency to fall madly in love with mortal women, who almost always gave in to his seduction and were later gravely punished by the jealous Hera (who was coincidentally the goddess of marriage).
Leto.
A titan, she was the goddess of motherhood and modesty. She was said to actually have been married to Zeus before Hera, and yet Hera tailed Leto while she was pregnant, preventing her from giving birth. Eventually she found the floating island of Delos and bore Artemis, who then (almost immediately) helped her mother to a different island where she gave birth to Apollo. Leto and Artemis were said to have had a very close bond of mother and daughter.
Apollo.
Apollo was the younger twin brother of Artemis and like her was embodied by the bow and arrow. (His were gold and hers silver.) He was also the protector of young boys and associated with the sun.