A Mirror Image

Mermaid / Mermaid
It looks like the same word, but each is totally different. The first word expresses the fairy tale, Disney-like, happy happy, fall in love type. The second is a pesky, obnoxious, conniving, manipulative yet oblivious type. In a similar spirit of monsters, there are many types of mermaids. Just the word doesn't reflect a common understanding of them.
Throughout the summer I have done a substantial amount of research on them. I have taken my children to the Cahoon Museam, Heritage Museam and Gardens, Shawme Pond, The great wide open Ocean, Cape Cod bay, We have looked online at mermaid figureheads and explored legends. The absolute best part about writing for children is sharing with my children. They are given an opportunity to explore and dig and find and ask questions and answer questions and imagine and uncover and see the world in a totally different light.
Now my challenge is to actually complete one of the few mermaid books I have begun. Which approach is the best, most successful and concise?
Here is a poll question for my followers and other readers.
Include pirates; yes or no