Ignore the "if they don't eat it they go without" crew. They clearly have absolutely no idea about parenting a child with additional needs who has sensory or food difficulties. I've got two autistic DC and we've gotten to a relatively good point right now, it's a been a right bastard over the years. I could have written a list like you a few years back - I sat on the pavement outside my house once and cried with frustration.
Bit of a weird suggestion - do you allow electronics at the table? Or have a TV on? I know this is terrible blah blah but actually we found that the distraction worked a bloody treat! Without the complete focus on the food, and being distracted by a favourite show, my DC have gradually gotten better at eating. It might not work for everything, but for those borderline things it might help - and it might help with any anxieties which are present. Texture/sensory issues aren't going to magically disappear but distraction is a very effective technique which I rely on for all kinds of issues!
Also, you might already do this and if I've missed it, I apologise but I never, ever comment on how much they've eaten, or look frustrated with food that's left over. Expectations and demands ramp up anxiety in autistic children/DC with associated sensory disorders and it makes it even more of a battle. One of the primary presenting features for autistic girls is anxiety, and that typically manifests as control. Although it sounds as if she has sensory issues, it also sounds as if there's a lot of anxiety/control issues for her too. Anything you can do to lessen demands/expectations/anxiety will help.
You'll have to judge what works best for you re filling up her plate vs doing a help yourself buffet style. I used to get very anxious with a big plate of food when I was with my ex as he expected me to eat most/all of whatever was on there. (I'm autistic). My DP now doesn't give a shite what I eat, and I feel totally fine with a full plate of food now because there's no pressure.
In contrast, my DS will eat what's served onto his plate and not a mouthful more. We're only just venturing into buffet-style eating now - he found that quite hard. One of the things that is usually recommended for autistic children is a defined "finish" - no matter what task you are doing. That can make a buffet tricky for some, because how do you know when you're supposed to have finished? Not having a defined amount of food can be more stressful and provoke anxiety about how much you "should" take. Different approaches work for different kids, depending on their anxieties. It's worth trying both and seeing what works better.
Good luck, I know how hard it is. And do push for the appointment - my DS was diagnosed at age 4, but his twin sister wasn't diagnosed til she was 10. Girls get missed by the system because it just looks like fussiness and anxiety but there's so much more going on beneath the surface.