The word familys is not a word although family's is.
Characteristically
zanous zanious zanies zaneful
The past tense of the verb to keep can also be used as an adjective (e.g. kept woman).
"Family" is from the Latin word familia, which means "family; household" and, originally, "slaves of the household". The word for an individual slave was famulus for a male, famula for a female.