Morveren the Mermaid

She dared to venture out one day
Beneath the ocean floor.
A sweet voice beckoned her to stay.
This mermaid longed for more.

Her father strongly cautioned, "No."
A tear fell from her eye.
"Be careful then if you must go.
I hate to see you cry."

Every night Morveren returned 
To hear her Matthew sing.
For human love is all she yearned
And all that it could bring.

Once staying longer than she ought,
Enchanted by his song,
She sighed with woe and soon was caught.
She'd done her father wrong.

"Please stay with me," of her he begs.
He cannot let her go.
This beauty with a tail for legs,
He loves her even though.

"I can't for I am of the sea."
She sadly turns away.
He says, "Then I will follow ye.
With ye is where I'll stay."

Again the two were never found.
Alas, but have no fear.
For Matthew's love songs still abound
If only you will hear.

Kathy Kehrli's Questions:

Do I have the ballad form down?

What phrases could be changed?

What would make the story better?