Grandma of the prophet? (5)
I believe the answer is:
moses
I believe this is a double definition.
'grandma' is the first definition.
(Grandma Moses was an American artist)
'the prophet?' is the second definition.
(Moses is an example)
'of' is the link.
(Other definitions for moses that I've seen before include "He led the Jews from bondage in Egypt" , "Hebrew prophet - basket used as baby cradle" , "Old testament leader" , "OT Lawgiver" , "Hebrew prophet who received the ten commandments" .)