My ex wrote apologising for the nieces outburst saying she didn't understand why she had done it and that she shouldn't have felt the need to say anything at all. She also said that she had stopped reading the blogs and that someone else had told her about the last few posts.
She also told me that I needed to stop apologising, that it served no purpose to keep living the guilt and that it was time for both of us to move on guilt free. She hopes that I can look to the future instead of re-examining the past. Now I think that I can only really do that if I do keep trawling through that past but I don't see that as an unhealthy thing to do.
Very gracious and brave things to say. I truly hope that one day we will be friends again.