@Amber-Lynn-Benton Hi, Amber. I really like the first two concepts.
In the first one I like the composition, it looks more symmetrical and gives you the possibility to play a bit more with the details, I think. I like that you made the mermaids interact with the title and the subtitle of the book.
In the second one, the shape reminds me of the Ouroboros (the snake eating itself) used on Michael Ende's The Neverending Story, which I loved. I may be biased on this, but I think it's a bit of a more bold design this one. Maybe if you make it a bit more symmetrical and somehow have the mermaids a bit more spaced - I'm not sure about the margin areas on the left and right. Hope it helps!