She probably had an account that had a very low number of iterations. LastPass never updated those unless someone knew to do it manually, so if it was an old account she likely had 5,000 iterations out of the recommended minimum of 100,000.
Based on your understanding, does my master password length sufficiently mitigate the low-iterations, or is decryption a realistic possibility?
But it's probably easier to just change your passwords anyway. At this point I wouldn't be suprised if the story gets even worse somehow.