Thinking about it - it's actually a very shocking slow burning portrayal of life after the death of a child. Pat and Tony, but Pat more obviously, always wear an air of tragedy that just can't be shaken off. Pat definitely gives the impression of continuously wading through glue.
And I guess that may be why she can seem an unattractive character to anyone who wonders why she's always so miserable - or maybe not miserable, just rather ....what's the word I want?