Hargan family Limerick

Hi there, I've recently been doing some enquiries attempting to trace some ancestors from the Limerick area, and have come to a bit of a dead end with links to the Hargan family. The only details I know are that the family is thought to have consisted of four siblings, possibly three brothers and one sister, with one of the brothers being called James, born approx 1955!? I know that isn't much to go off, but any small pointers in the right direction would be greatly appreciated. Thanks very much, Matt