DD2 has some language oddities, amongst other things. I asked a lovely SLT their opinion (they are not local, it was an off the record chat). The SLT said that the phrases I quoted sound pretty disordered and I should press for a SLT referral.
Yesterday, DD2 was off sick again because she had been feeling very sick (genuine head over the toilet bowl begging for a bowl stuff, not just 'ooh I feel sick, wink wink). I took her to the GP again. It turns out a referral to DD1's paed (DD1 has complex SN, special school) was done on 16th November.
Today, I took DD2 into the school. Her teacher said she's been 'observing DD2' and she's pleased to report that she's mixing much better at school. She's also noticed that her language is 'very precise' and 'much more precise than others in the class.' For example, saying 'can I go outside please, to do skipping' when other children would just say 'can I go outside?' I tried to explain to the teacher, that it is that sort of thing that is precisely the issue - there are times when she is incredibly precise, because everything has to be 'concrete' then there are other times when she says stuff that is quite quite barmy. Today, for example, I asked her if she had lost her cardigan and she said 'No Mummy, I desperate not! I don't lose things.'
What the teacher is seeing as 'advanced' is just a symptom of the issue DD2 has. I've tried to explain that I don't think DD2 is 'thick' or 'behind' - it's nothing to do with that.