As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIR RETURN, ABOUT 30 MIN OUT THE AFT FA ADVISED HE HEARD THE LAV SMOKE ALARM. THE FA CHECKED ON THE PAX AND WHEN THE DOOR OPENED HE SMELLED VAPE EXHALE PASSENGER WAS QUESTIONED IF SHE VAPED IN RESTROOM AND SHE REPLIED SHE DOES NOT VAPE AND HAS ASTHMA. THE FA ADVISED IT RESEMBLED THE SMELL OF MARIJUANA PERFORMED OPS CHECK OF AFT LAV SMOKE DETECTOR IAW AMM. OPS CHECKED GOOD.