Fabulous wife, but she just had to run away with a writer! (8)
I believe the answer is:
penelope
'fabulous wife but she just had' is the definition.
I can't judge whether this definition defines the answer.
'run away with a writer' is the wordplay.
'run away' becomes 'elope' (I've seen this before).
'with' is a charade indicator (letters next to each other).
'a writer' becomes 'pen' (something which writes).
'elope' put after 'pen' is 'PENELOPE'.
'to' is the link.
Can you help me to learn more?
(Other definitions for penelope that I've seen before include "girl" , "lady" , "Waiter" , "Ulysses' faithful wife" , "Wife of Odysseus or Ulysses" .)