Aer Lingus offer unaccompanied minor services to minors aged between 12 to 15 years when they travel alone. Aer Lingus UMNR service is only available on the airlines direct flights. To book a flight for your child, Familiarize yourself with the Aer Lingus unaccompanied minor policy, or go through the Aer Lingus website or dial their customer service.
Source: https://www.airlinesunaccompaniedminor.com/aer-lingus-umnr-policy