I waded through "The Grace Girls" in the hopes that it would pick up somewhere along the line, but it simply didn't. I found both the characterisations and the language (particularly the constant references to "my daddy" and "my mammy" in the conversations between the two sisters) annoying, and despite the small hints that something interesting might develop, it never did. A particular example of this is the rather confusingly tagged on and ultimately meaningless storyline about a murderer in the midst of the community.
This genre is really owned by Maeve Binchy and Rosamund Pilcher, and O'Neill comes nowhere near to attaining the same levels of engrossing storytelling. At no point did I feel encouraged to develop an easy and natural empathy with the characters. I recommend avoiding this novel and finding a better use for your time.