Worried her title can become dangerous if not passed on (5,6)
I believe the answer is:
chain letter
'dangerous if not passed on' is the definition.
I can't judge whether this definition defines the answer.
'worried her title can' is the wordplay.
'worried' is an anagram indicator (worry can mean to interfere with or disturb).
'her'+'title'+'can'='hertitlecan'
'hertitlecan' anagrammed gives 'CHAIN-LETTER'.
'become' acts as a link.
Can you help me to learn more?
(Other definitions for chain letter that I've seen before include "The clarinet (anag.)" , "Fraudulent scheme" , "What may arrive in the post" , "one sent mushrooming?" , "Fast-spreading communication" .)