I like them both, but the red one takes the cake. Sure, red roses are a classic, but this red is just so deep and rich. The bluish one is nice and creative, but it just blends so much into the background. The change in color just steals it's brightness, causing it to seem almost dull and lifeless.
The green-blue one is FAR more unique and beautiful, I would go with that one personally But it also depends on what type of book it's for. I would ask the author (if possible) which one she thinks would fit.
There is a little misunderstanding, none of these two are selected for her book. The red version was my second layout for her, the green-blue one is my personal editing. She decided for the first layout that I have done which you can see here: [link]