The classical scheme of the Twelve Olympians comprises the following gods: Zeus, Hera, Poseidon, Demeter, Ares, Athena, Apollo, Artemis, Hephaestus, Aphrodite, Hermes, and Dionysus. The Greeks believed them.
Because her husband Zeus is the king of Olympians and therefore Hera is the queen of Olympians
the Olympians
Their ancestors the Titans
Yes.
The Greeks believed in many different Gods, I don't know an exact number but there are over 40 different Gods of varying levels of importance. However there were twelve Olympians, which are the Gods most people are familiar with.