Help needed. This is my Sensation Peace Lily, I got her several weeks ago. She is massive. I keep it by the front door in its own space and it gets shaded light like requested to have. Recently she's begun to have these yellow and brown spots. Could it be due to having low humidity in the house? I'm buying a small humidifier to see if that helps the problem. I am looking for any tips from other owners of peace lilies.