Lucky thing, so he - or she - makes out (9)
I believe the answer is:
horseshoe
'lucky thing' is the definition.
(I've seen this before)
'so he or she makes out' is the wordplay.
'makes out' is an anagram indicator.
'so'+'he'+'or'+'she'='soheorshe'
'soheorshe' anagrammed gives 'HORSESHOE'.
(Other definitions for horseshoe that I've seen before include "One could be lucky" , "Lucky item?" , "What a farrier fits" , "Lucky charm" , "Steed's footwear" .)