I may have missed this but whose claim qualifies for the car? If the car is for a specific child, it’d be harder to justify school transportation for that child, as @kezo says, the councils have cottoned onto the fact the car should be for their use. If it’s for an adult’s use, then getting transport for the children could save you several problems.
There are 5 seater EVs that fit both the bill and requirements. For example the Enyaq will do the range and the grant covers the SE L with the plus pack. However, the 5 seater problem remains.
I'm Autistic, if I say something you find offensive, please let me know, I can guarantee it was unintentional.
I'll try to give my honest opinion but am always open to learning.
Mark