Woman from north involved in Muslim festival (4)
I believe the answer is:
enid
'woman' is the definition.
(woman's name)
'north involved in muslim festival' is the wordplay.
'north' becomes 'N' (abbreviation).
'involved in' is an insertion indicator.
'muslim festival' becomes 'eid' (Islamic term for festival, eg Eid al-Fitr).
'n' put into 'eid' is 'ENID'.
'from' is the link.
(Other definitions for enid that I've seen before include "Writer of children's books, d. 1968" , "'... Blyton, children's author (4)'" , "Arthurian wife" , "W - - Blyton" , "Dine with this girl" .)