It sounds like an argument over semantics to me, from people who really don't have the training to understand any difference between the definitions. Fiddling while Rome burns...because in the meantime, what does tis mean about the sort of work they are giving her?
My response would be, I don't care what they call it as long as she gets the level of education she can handle and that she is entitled to. If the change in label allows them to justify giving her the simpler work, then go for it. But if they are merely moving words around on paper in order to find a way out of having to educate her, then go for their jugulars.
Before going back to your daughter's specialist to nail down a diagnosis, find out what the consequences of each diagnosis means, in the education system. For example, for difficult child 3 for some time - the autism label was excluding him from correspondence education even though he met all criteria and was a classic case. Then when we finally found a loophole, difficult child 3's anxiety (which was understandable given the emotional damage done by mainstream when he needed to be correspondence) was also a label which gave the educational authorities the right to over-ride the medical diagnosis and recommendations. We had to find ways to get the diagnosis worded very carefully, to get what we needed from the education system.
So rather than look up definitions medically, find out exactly what the definition means in the education system, especially since they're the ones nitpicking over labels.
Sounds to me like someone is playing silly burgers. (OK, I can't use the more appropriate term on this site).
Marg
Marg