Her father is Zeus: she is therefore related to the Olympians.
Apollo
Often, heroes were the children of the gods also known as demigods halfbloods or offspring
Athenas dad was none other than the king of the gods of olympus, Zeus
Greek gods are as real as any other gods.
Usually the Greek gods and goddesses were born of other, older deities.
humans and other gods
No, Greek gods and goddesses can not kill each other. All the Greek gods are immortal. They can however be destroyed, but shortly after they are defeated they respawn. This s true for demons aswell.
Athena's hair is brown but some people think it is black or blonde
Athena lived with the other main Greek gods on Mt Olympus. The Greek gods are not in our chronology.
Other Greek Gods.
Most Greek gods were depicted in human form.
Circus Olympus is very clearly based off the the ancient Greek gods. It's not hard to do.