I just bought some mermaid themed yarn to crochet a blanket for my daughter.
Will you be using a mermaid tail crochet pattern?
Yes.  I will chose one that has an open end so it is easier to pull up.
What color yarn did you choose?
I chose some skeins of yarn that have variated colors of purple.
Will you be using the mermaid stitch, it isn't all that common, from my understanding.
No.  I like to use an easier stitch so that I can watch TV while I crochet.  I am used to the normal loop and perl so I don't make mistakes.
From what I understand, you can accomplish a textured vertical rib when using "knit two, purl two."  I that the look you were going for?
Yes.  It will look so nice for my daughter!
That sounds nice.  I am sure it will turn out nicely.