Taking mother's place at home, developing clear options (2,4,8)
I believe the answer is:
in loco parentis
'taking mother's place at' is the definition.
I can't tell whether this defines the answer.
'home developing clear options' is the wordplay.
'home' becomes 'in' (to be in is to be (at) home).
'developing' is an anagram indicator (letters developed into a new form).
'clear'+'options'='clearoptions'
'clearoptions' is an anagram of 'locoparentis'.
'in'+'locoparentis'='IN LOCO PARENTIS'
Can you help me to learn more?
(Other definitions for in loco parentis that I've seen before include "instead of the parents" , "As a teacher may be" , "old man?" , "Trying to be mum" , "acting as guardians" .)