Thankyou everyone for the replies.
Millie saw the speech therapist at the hospital this morning and he did (as far as possible) reassure me. It seemed like a much more positive meeting, which is what I needed, it was all starting to feel a bit doom and gloom before! The sessions in our home are going well. Millie is responding to the makaton signs the therapist does with her, and has started to do a few herself. I'm trying to keep this up at home too, but my knowledge of makaton signing is limited right now. I have had my name on the waiting list to do a course for ages, but apparently they have not yet announced when the next course will even be run! Thankgod for Mr Tumble!!