Thank you everyone for your replies.
The details for the 1891 census are as follows:
Reg district: St Austell
Sub Reg district: Grampound
ED, Institution/vessel: 9
Piece: 1825
Folio: 86
Page: 8
That census has been transcribed as Blom but when you look at the image it definitely says bland and the children names and ages are all correct.
I had seen the story about the Sarah Hughes who's baby died and wondered if the aunt could be our Sarah. She just doesn't seem to exist before 1871. I did find an article that stated many Romany's had a given name and home name (we have seen this with a few people on our tree). I wonder if she could have gone by a different name.
As many of you have said records may not have the answer. We have been able to do so much of the rest of the tree it just seems a shame the maternal line is more tricky.
I am happy to share my tree on ancestry with anyone if that would be helpful. I really do appreciate all the help.
Best wishes