Sadly we said goodbye to Max this evening. :(
Despite things looking promising this last week or so, this evening she began to have problems standing up and holding her head straight.
Vet ordered another blood test, which proved normal, but my DM found her lying by the dustbin outside this evening; she came in but could hardly walk.
We took her to the emergency vets, but she was unable to do anything for my poor old lady (said it was a neurological problem) So we made the decision to have her PTS. We stayed with her as she passed away peacefully.
Will miss her. RIP old girl