Hi saintly:
Just a word of caution: This dropped kerb and marked parking bay, initially created for a specific reason, would be on part of the road/highway, hence bringing it under road traffic legislation.
Therefore, the fact that you've decided that, as a disabled driver, you could make use of it because your neighbour doesn't use it doesn't mean that the Council will agree.
The reason being that should you, or anyone, park there and your neighbour, for example, has visitor(s) wanting to park on her driveway, you would be causing an obstruction and could pay for it (literally).
You would need to either have the dropped kerb relocated to outside your property (costing the Council considerable expense), and have your neighbour's dropped kerb reinstated(more expense). Unless that is feasible and unless you could be prepared to contribute towards the cost, it may prove very problematical.
It also sounds as if you and your neighbour aren't seeing eye to eye which may be liable to cause further tension.
Good luck.