I have just received an email from my cousin Lyn with some exciting new documents which she has uncovered in her loft.
The first is the confirmation certificate of Harriet Jane Hopkins (she was often called Jane) on Alderney on 10th August 1884:

The second is the actual marriage certificate of Harriet and Thomas Jackson. Up until now we only had a copy of the church records (note Harriet is Jane Harriet here):

For me these are quite poignant, when Thomas returned to Guernsey in WW2 and the family were concerned that they had not heard from him:

… and finally the news the family dreaded that Thomas Jackson’s had passed away on 26th August 1943 :

It looks like the family had to wait 8 months to hear this news.
The missing piece of the puzzle is still verification of Harriet Jane’s mother, but, since many records were lost or destroyed on Alderney during the evacuation of WW2, it is very unlikely anything will come to light now. Common sense is that her mother’s name was Jane, but we have no proof of that.
Harriet is the protagonist of my first novel Riduna.