One of my best friends at school - a long time ago now! - always wanted to be a vet, talked about it with lots of teachers, had lots of encouragement and support.
During our A levels (where obviously she’d chosen the subjects needed for veterinary science) our head of sixth form had to break it to her that she was obviously not going to get the needed grades.
She was devastated, completely spiralled about the fact that she’d been (she felt) lied to and misled for so long, fixed on the idea that the teachers had secretly been laughing at her, and dropped out of a levels.
She then got some kind of random office junior job, when I last heard from her she was in her mid 20s and going back to college to do some kind of animal care course. Because she’d finally realised that she wanted to work with animals, and being a vet wasn’t the only way to do that!
I’ve always kept that in mind when talking about careers with my kids and niblings. If they say they want to be a lawyer, I say great! What do you think you’d enjoy about that? And then chat about all the different roles in the legal field and outside it that might use those skills. One wanted to be a doctor until we really talked about it and she realised actually all the elements that appealed to her would be possible as a nurse instead.
It’s easy as a young kid to fixate on the obvious job within a particular field (postman pat delivers packages to the vet, not the veterinary assistant, etc you only really hear about the obvious jobs). But it’s IMO down to parents and teachers to be supportive but also informative.
I also have SEN kids: in your shoes right now that the teacher has messed this up, I’d switch to just supportive. Oh how great the teacher thinks this is realistic, lovely. I know you’re working hard, what would be helpful for your revision? How can I help?
And then after sitting the mocks but before results a bit of chat about other options just as a backup, and then see what happens.