Can anyone identify this series?

[Charlotte]

Think I posted this on the Girlsown Google group years ago, but no-one knew, not even any Irish members. No-one knew on the Chalet School forum. Wikipedia seems to be no help either, in the Irish childrens' author section. Perhaps it was not by an Irish writer, despite being set in Ireland. It was a series of childrens' books set in Dublin, that I used to get from the library in the 1980s/90s. I think the stories centred around a group of kids and an old derelict watermill on an island in a river (the Liffey, presumably). Can't remember any more than that.
Anyone recognise that, I am quite sure the books existed?

[Claire]

Hi Charlotte, I'm trying to put my thinking cap on and I'll also do some networking. The Irish author throws me a bit but if it is not an Irish author, only set there, there are more possibilities.