Police in Ireland are still searching for the killer.
Members of Ashling’s family joined local people in Tullamore where she lived, and there were other gatherings in Belfast and Dublin.
Sky’s Senior Ireland correspondent, David Blevins, reports.
SUBSCRIBE to our YouTube channel for more videos: http://www.youtube.com/skynews
Follow us on Twitter: https://twitter.com/skynews
Like us on Facebook: https://www.facebook.com/skynews
Follow us on Instagram: https://www.instagram.com/skynews
For more content go to http://news.sky.com and download our apps:
Apple: https://itunes.apple.com/gb/app/sky-news/id316391924?mt=8
Android https://play.google.com/store/apps/details?id=com.bskyb.skynews.android&hl=en_GB
Sky News videos are now available in Spanish here/Los video de Sky News están disponibles en español aquí https://www.youtube.com/channel/skynewsespanol
To enquire about licensing Sky News content, contact clipsales@sky.uk