Just found this on the Leap Card website.
A family of up to 2 adults and 4 children can use buses, luas an Darts for a tenner, including Airlink and Nitelink for €10.
What's going on here?
https://about.leapcard.ie/leap-family-card.
Available from 1 March and must be used by the end of the year, with a maximum of 2 cards per order.