It struck me as significant.
Bless the lovely softies walking among us who think it would be quite nice really if Catherine forgave TLR!
Sadly, forgiveness isn't a switch we can just flick - if only it was Even if you decide to forgive someone it can take a lifetime of work.
There's a wonderful book "If you sit very still" by Marion Partington describing her forgiveness process. Her sister Lucy was one of the tragic victims of Rose and Fred West. She describes the hatred and rage she felt for them - and how she realised it was both keeping her alive and destroying her, and she made a conscious decision to let it go. It took years and it was far from easy. One of the things that helped was when she learned what dreadful lives the two of them had had as children - how frightened they had been, and how they had been corrupted. The pity she felt for the child that used to be Rose overwhelmed her. It enabled her to detach herself from that rage and pain and hatred, and begin to live properly again.
If Catherine could open herself to that - feeling pity for the child that was Tommy, the neglected, probably battered, possibly sexually abused, definitely terrified child of a heroin-addicted prostitute, seeing and hearing and experiencing things no child should ever see or hear or experience - if she could feel sympathy for baby Tommy, toddler Tommy, child Tommy - then perhaps she could start to let go of the hatred which is destroying her and her relationships.
It seems that Ryan, young as he is, already has that insight.