Hi lidybut
I am pleased that we have been able to help you on this. It does look as though you have been on the right track, and I hope that the marriage certificate will also help when it comes. Although if Mary was committing bigamy, we can't really predict exactly what info she might have given!
I didn't see Mary in Woodshaw, but I didn't have time to look at all years. I will recheck. Albert was there in 1959. Mill Hill was right, but have you got any other possible addresses she might have lived? The post war Leicester electoral registers are not indexed.
It looks like Mary's sister Alice died in Leicester in 1954, so you probably won't remember her. But I guess that Mary (and Albert?) went to Leicester because Alice and her mother were there (I don't know about the other family members)
As your dad was in a children's home, I wondered if perhaps Arthur Taylor had died, but it's such a common name that it might be a hard job to find out when. And there is a married Mary Taylor with the right birth date in 1939, but not with family. Thus I don't know if it's the right one.
I can't advise much about your photos, I have never put one on here and the only attachments I have added were done with some difficulty!
Perhaps you could try it out with just the penny first, and see how it goes?
Good luck.
John