Family member doesn't stop walking (7)
I believe the answer is:
stepson
'family member' is the definition.
(son of one's spouse)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for stepson that I've seen before include "Child from a spouse's former marriage" , "younger member of family" , "second family member" , "could be issue for partner" , "Male offspring of partner's former marriage" .)