Hi pinkElephants,
to All Things Plants!
Just a guess but I'm thinking the drying leaves could be due to lack of humidity as well as very dry air ... which happens in heated homes during the winter months.
Peace Lily (Spathiphyllum wallisii) as well as other Peace Lilies are tropical plants that love warmth and high humidity. You can sit the plant on a saucer or tray of moist pebbles (just be sure to replace the water in the saucer/tray as it evaporates) which will raise the humidity levels around the plant but it's important to keep good air circulation too and a small fan on low speed will help with that.
