So, a couple of days off writing and emotions going up and down and roundabout again - not helped by even more sickness. Looking forward to feeling fit and healthy again sometime soon.
Talking to more people now about the situation and I think it helps..... but am swinging between thinking Sasha does have this problem and wondering again whether she is just a 'normal' toddler. They all have their moments, and in fact Sasha's behaviour is often better than her elder sister's! She seems generally more content - but I have to admit that I have probably altered my behaviour to let her be more settled. I think the difference is in how the little things seem to stress Sasha (and therefore me!) out rather than just upset her as they would Tamsin, but I can't really be sure anymore. Need some time and space to think things through, and our chance to talk this through with a professional can't come soon enough.
Am happy though that she seems to be enjoying her extended hours at nursery, and she does still show signs of development. This morning she attempted to read a book to me at the kitchen table, and although the speech isn't clear, the intention and intonations definitely were. Even as little as a month ago this is something I couldn't imagine Sasha doing - any more than 2 seconds a page was too long for her to take interest in any book!
Will try to continue to record both the improvements and the differences over the coming weeks...