Ireland medical card for retired uk migrant?

My 67 yr-old retired mother is considering moving from the UK to southern Ireland, but it is unclear if she will be eligible for the medical card. She has no savings to speak of, her income a mixed state and occupational pension of ~ �800 / month (this before living expenses, e.g., rent). This apparently has to be means tested, and a PPSN (Personal Public Service Number) has to exist (presumably, something only irish people have). As the UK is part of the EU, is all this bureaucracy just a formality, or is it difficult to get health care in Ireland as a non-native?