Great Aunt Marcie
Unseen Person
Name Marcie
Age 60's-80's
Gender Female
Actor None
Film Appearance? No
Online Appearance? No
Book Appearance? Yes (Mentioned only)

Great Aunt Marcie is the great-aunt of Greg and the sister of Grampa and from Susan's side, she adopted a 3 or 4 year old toddler named Cecil and is Greg's adoptive's uncle and is considered an adult in the family.