What roles do the grandmother and her daughter play in the earth's creation?

The roles the grandmother and her daughter in the earth's creation are:

The Sky-woman, who later became a grandmother exposed the Sky-world to the ocean world beneath. She gave birth to a daughter in the Sky-world.

The daughter Sky-world gave birth to grew up to become a beautiful woman and married Turtle-man. She conceived and gave birth to twins before she died.

One named Sky-holder was good and the other, Flint was evil and bad tempered. It was these twins who are said created.

Explanation:

This is a Creation Myth which is based on life in the Sky-world. It is a story which started from the spirit-world and ended in the spirit-world.

in what story are we looking at?

i guess you are missing the idea that has to be supported, am i right?