You have really won a Pisces over if you have gotten to the core of her conscience. There's great freedom in not having to lie or deceive anyone in any way. As far as manipulation is concerned, if you give your fish room to express her mistakes or little attractions, you'll have quite the bag of honesty. It is more difficult to make her feel 100% secure though-- sometimes it bores us!
I think while we might seem like a complex sign, Pisces are often very biological, but the characteristics we are looking for have more to do with a mature understanding of the universe (not just looks), and the security and confidence that comes with it. That's what we know in our hearts will drive our species forward, I suppose. This in itself is rare, but when you keep us on our toes as well, then that's a keeper. However, because it is rare to find people who have "found" themselves, we often settle for them, but our minds wander to those that stir up our excitement more. But we know you are a rarity, so we would hardly act that stuff out...
I am dating a Capricorn now. Although he is much less of a kook than I am, I am very satisfied... He is very at ease with himself and gives me ample room. He is definitely not organized, and I'm having to go out of my nature to keep him so... And he does have a jealous streak, which has relaxed in time.