First of all, I do think the concept and basic idea of this book is good. I believe in purity, and think that you should strive to keep pure not only physically but emotionally as well. Many people tend to overlook the emotional aspect.
BUT
There are some dangerous ideas in this book that could be harmful if taken too seriously. I for one would not let my daughter read it without us discussing it heavily together. The author goes *way* overboard on guarding your heart. Yes we need to guard our hearts closely, but if you close off every little feeling, eventually your heart will become hard and cold as stone. And when the right guy comes by, you won't even be open to the blessings God has for you. God gave us the ability to feel things and experience emotions. It is a good thing, not evil. There is nothing wrong with having a crush on a boy when you are a teenager. Yes you might get hurt and believe me young love can be painful. But you know what? It doesn't destroy you, it's not the end of the world. Your "future husband" isn't going to be upset and disappointed that you had previous crushes. It doesnt make you damaged goods. Come on people. We're talking about young love, "I like him/he is cute/He smiled at me squeee" it's not like you are making a HUGE life mistake that will haunt you all your life. This book is over dramatic and just plain silly. Keeping yourself emotionally pure can also be motivated by simply not wanting to get hurt. That is selfish and immature. Life hurts. Period. You can't avoid it. God will always get you through it. Having fear is sin anyway isn't it? Why can't you just trust God with your feelings? Why is that not enough?
I also didn't like the idea of every time you feel something for someone you give a piece of your heart away, an eventually there won't be anything left. That is NOT true. I love God, my husband, my parents, my daughter, my friends, extended family...and oh well by the time I have another child there just won't be any left! Sorry! That is just dumb. If you have the love of God in your heart, your love will never run out.
So yes I believe in keeping your emotions in check, but please girls, don't take it too seriously. Trust God, but don't fear what you feel.