Besides the great resources caryn pointed you too, the PF also has information on the website that you might be interested in. Various researchers have looked into nutritional theories of preeclampsia, but so far there has not been much to come out of it. http://www.preeclampsia.org/component/lyftenbloggie/2012/02/29/121-analyzing-the-nutritional-hypothesis
Many people would be very happy if following a diet would be the remedy for PE, but unfortunately it is not that simple. If you get PE, your placenta is the culprit. Delivery of the placenta is the only known cure to start the body healing.
Of course, eating healthy foods and maintaining a general healthy lifestyle during pregnancy (and outside pregnancy too of course!) is important, but it is not known to influence whether you get PE or not. There is also evidence that some diets could potentially be dangerous, so do be careful.
You should also check out the Health Information section about recurrence rates (http://www.preeclampsia.org/health-information/faq#fifteen
) and as caryn mentioned, consult with a SMFM so you can get a personal risk assessment done. That should be reassuring and help you and your partner to have a lot of good knowledge and care if/when you decide to try again.
So glad that you and your little girl are doing well! Let us know how the decision process goes. We are all here to support you.