Hi there- my mom's beloved snake plant that I inherited has been slowly wilting and looking like it is failing over the past many months. Too much water? Root rot? I have no idea. Please someone send help- what to do to save it...it has been in the family for so many years! thanks so much! ps- it sits in a sunny window and I water it about once/week to 10 d....I wait until the top soil is pretty dry...thanks! thanks!