Update: Gardaí have located Alannah Corrigan safe and well.
Alannah Corrigan was last seen in Dún Laoghaire on Wednesday morning.
She is described as around 5 feet in height, of slight build, with black hair and blue eyes.
She is known to frequent the O’Connell Street/Mountjoy areas of Dublin.
Anyone who has seen Alannah or who can assist in locating her is asked to contact Dun Laoghaire Garda Station on 01 6665000, the Garda Confidential Line on 1800 666 111 or any Garda Station.