Lou, full-time 1:1 is a battle everywhere. J's nursery had spelled out at length how much he needed full-time 1:1 for health and safety (he is a runner and also pretty much constantly violent and destructive at that age - would attack with knives, scissors, books...whatever he could get his hands on and bit, hit, scratched and head-butted children and staff pretty mich every day even with 1:1 ). Even the ed. psych, within the constraints of what she could say, wrote that he needed an "extremely high level" of 1:1 at school. He was turned down twice for Statutory Assessment and then, after Tribunal application and letter to MP, was assessed and given 18 hours or something of 1:1. The school and governors of the place he was due to attend complained and were basically told to sod off, as was I, so they had to fund the extra for 3 years to cover him for full-time 1:1.
After 2 years, I re-applied for full-time, with the school's consent, and they still said no . I then came up with a list of number of violent/ dangerous incidents with the school and number of incidents needing restraint, and we sent that to the LEA and to my MP. It was quite shocking . He had also had his ADOS test which proved that he had quite severe difficulties and confirmed the dx of autism. The MP wrote a shitty letter to the LEA and I also applied to Tribunal. They tried then to offer 25 hours (here, the school pays for anything 25 hours or under out of their budget) but I said full-time or nothing. They agreed and he now gets 33 hours + 5 hours for preparation time for the TA. It's all paid for by the LEA as he is a low-incidence statement over 25 hours.
I wish, in retrospect, that I'd gone to Tribunal in the first place when the first Statement was shite.
My point (eventually!) is that you need written evidence from as many people as possible stating clearly the need for full-time 1:1 and what would happen without it. I suspect that they will try to get away with it because she isn't dangerous to others but your priority is obviously that she's not dangerous to herself! The EP is naughty saying that the school would just have to provide whatever she needed - you have the right for have full-time specified in the Statement so that dd has what she needs and school can't wriggle out of it by saying 'oh, well she's OK during assembly by herself' or whatever. They have budget constraints and might have to cut what they can offer her without full-time specified, but they can't do that if it's in her Statement. I hate it when crap statements from the LEA pit the parents against the school - LEAs need to suck it up and specify what is needed.
I also think that MP letters and Tribunal applications, ime, are unfortunately far more powerful than anything a parents says or writes to the LEA. My advice is to use the EP's words about dd's complexity and uniqueness against her to say 'well then, she's obviously low incidence as very few others will have needs like hers'.
You will get there. It may take a while, but if that's what you and others say she needs, the LA should give her that. They can't have a blanket policy not to give full-time and I had to remind my LA of that when they tried to tell me that they never gave full-time. They do now .
Good luck with it all!