The white part of the peace lily is curling & brown. What have I done, or what do I need to do?
This is natural as the flowers start to drop. If you are starting to see this on the leaves instead, then you can start to worry. There is nothing to be done but to cut the flower start to the base when it is completely dead. Here is an article that will give you more information on the care of the plant: https://www.gardeningknowhow.com/houseplants/peace-lily/peace-lily-plants.htm