Did Miriam Author Part of the Bible?

There is an obvious chiasm in Exodus 1-2 in the story of Moses' birth and adoption into Pharaoh's house. The chiasm includes at least Exodus 1:22-2:9, and possibly as much as Exodus 1:5-2:15.

This image shows the clearest segment:

Here is the expanded chiasm, which I think is correct:

A .v8-19 - Egyptians oppress Hebrews. Midwives rescue. Answer demanded. Escape.
B ...v20-21 - God's favor on the Midwives and growth of their families.
C .....v22 - Pharaoh said, "Take the son away. Let the daughter live."
D .......v1 - Amram went and took his wife, Jochebed.
E .........v2 - Jochebed conceived and bore a son.
F ...........v2 - Jochebed saw that the child was fine, took pity on him, and hid him for 3 months.
G .............v3 - Jochebed went to the river and hid the child in a basket in the river.
H ...............v4 - Miriam stood at a distance to learn what would happen.
G .............v5 - The princess went to the river and found the basket in the river.
F ...........v6 - The princess revealed the child, saw him crying, took pity, and recognized him.
E .........v7 - Miriam found a woman who had born a child.
D .......v8 - Miram went and called the child's mother, Jochebed.
C .....v9 - The princess said, "Take the child away. Pay the woman her wages."
B ...v10-11a - The princess's favor on Moses and his growth into a man.
A .v11b-15 - Egyptians oppress Hebrews. Moses rescues. Answer demanded. Escape.

Chiasms are always fascinating. The most interesting part is usually at the center, and this one is no exception. Miriam is at the center of a chiasm on the birth, near death, and adoption of Moses, and not just Miriam, but her observing and studying the process of Moses' transformation from Hebrew to Egyptian and back again to Hebrew.

What does this mean?

It probably means that Miriam was the source of the first part of Exodus; it might even record her exact words. How do we know what happened with the midwives and Jochebed and the basket and Pharaoh's daughter? Miriam witnessed it all so that Moses could his story as seen through her eyes and possibly even her words.

Knowledgeable Bible students will recall that this isn't the only extended record of Miriam's words. Exodus 15:1-21 contains The Song of Miriam.