Being a friend to one's parents' sisters, she's targeted! (4,5)
I believe the answer is:
aunt sally
'being a' is the definition.
I can't tell whether this defines the answer.
'friend to one's parents' sisters she's targeted' is the wordplay.
I cannot really see how this works, but
'friend' could be 'ally' (an ally is a friend or supporter) and 'ally' is found in the answer.
'she's' could be 'aunts' ('she' could refer to an aunt) and 'aunts' is found within the answer.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for aunt sally that I've seen before include "Deliberately easy target for criticism" , "Fairground game - target for insults" , "Shy" , "Fair target" , "Target of general criticism, as in throwing game" .)