A engagement ring is given in contemplation of marriage. If the marriage does not happen you get the ring back. However, once the marriage takes place I believe she gets to keep the ring.
I am a former federal and State prosecutor and now handle criminal defense and personal injury/civil rights cases. Feel free to check out my web site and contact me at (212) 577-9797 or via email at Eric@RothsteinLawNY.com. I was named to the Super Lawyers list as one of the top attorneys in New York for 2012. No more than 5 percent of the lawyers in the state are selected by Super Lawyers. The above answer is for informational purposes only and not meant as legal advice.
The engagement ring is given in contemplation of marriage so you won't get that back, since she married you. The wedding ring was given at the time of marriage so she gets to keep that. In the context of the divorce, you can make the rings a part of the settlement. Aside from that, they are hers to keep.