Sleep with family linen item? (6)
I believe the answer is:
napkin
'linen item?' is the definition.
'sleep with family' is the wordplay.
'sleep' becomes 'nap' (a nap is a short sleep).
'with' means one lot of letters go next to another.
'family' becomes 'kin' (synonyms).
'nap'+'kin'='NAPKIN'
(Other definitions for napkin that I've seen before include "Protective cloth square donned during meals" , "Cloth rectangle worn at mealtime" , "Small piece of table linen" , "Cloth used at mealtime" , "Cloth square worn while eating" .)