Woman’s lines, penetrating even for a poet (5)
I believe the answer is:
ellen
'woman's' is the definition.
(woman's name)
'lines penetrating even for a poet' is the wordplay.
'lines' becomes 'll' (I've seen this in other clues).
'penetrating' is an insertion indicator.
'even for a poet' becomes 'een' ('e'en' is an archaic or poetic term for 'even').
'll' placed inside 'een' is 'ELLEN'.
(Other definitions for ellen that I've seen before include "Girl's name" , "Girl" , "It could be Terry" , "MacArthur, round-the-world yachtswoman" , "Woman" .)