Thank you thank you thank you - I had been wondering if the other site had it wrong.
I had a newspaper clipping of the Jane-William marriage but not the Jessie-Thomas event.
It's a quite sad occasion later on as Jane and William had a baby daughter October 1875 - she died as a baby, her mother Jane died also in October.
Then a daughter was born to her sister Jessie in November 1875 and they gave their daughter the name of Jessie's deceased sister's baby, plus the name Purves included in the child's names.

Thanks again for taking the time to check for me.