Thank you both. I actually felt really hurt, which is, of course why I want to lash out. When I read it with its "my mother" in every sentence and talking to us as if we (my daughter and I)are his employees, my blood boils and I am just not an angry person.
Apparently he also knows all the ins and outs of the issues with Mum because he talks to her once a week (92% of the time, according to his letter) and she, the poor, darling, 94 year-old frail lady with Alzheimer's, tells him what is going on! No doubt we should use him as our secret weapon for diagnosis in the NHS as he can perform this wonderful trick. He used to ring her at 11.00 p.m. on the same day each week but he has changed this, perhaps because he has finally realised this is to late for Mum, but, as he doesn't let us know (her probably tells mum but she will not remember) when this is going to be she is not sure if he will ring on the Sunday night or if he will ring at all.
Thank you, thank you for being here and understanding.