I would think the best person to answer that question Mark would be a doctor who was personally involved in your mother's care.
Im sorry if this comment sounds less than helpful as it is obviously something you feel you want to know. I have to say I have no idea of what stage my own mother is at and it's not something I even think about very often. However, people are different and lots of people probably feel as you do. I had it in mind that there were actually six stages, rather than ten, but could be wrong.
Dear Mark, I can fully understand a 'need to know'. Knowledge is power, I believe the saying .... or at least provides us with some sense of control over a given situation. The problem with 'stages' - even if we could accurately define at which one anyone is at .... is we then have no definite answer to 'how long will this stage last?'
This has been one of the toughest challenges for me in terms of my mum's diagnosis - unlike others in the family where there has been a more definitive prognosis - even if that prognosis wasn't good ...... it is so hard to grapple with an unknown - let alone a 'known' - especially when you are in the midst of grief anyway ....
That for me is what makes this disease so unique and so hard for us all - that every person affected is so unique and there is nothing definitive about it - if that makes any sense at all?
Sorry, Mark, probably of little help - other than I feel exactly like you and wish there were more answers,