I have not in any way disparaged said member.
So lets break down their remarks:
"If her neighbour's drive has been damaged by their actions, she is liable."
IF being the operative word - the NDN would have to show before and after conditions of their driveway to determine/prove that damage has been caused. None of us here can know that except maybe the OP.
"On the information posted, her neighbour may have a valid claim. However, that doesn't necessarily mean the neighbour can claim the full cost of resurfacing her drive."
May have a valid claim is key. Not that the NDN does have a claim.
The NDN claim would struggle to justify them wanting the OP to cover the cost of an entirely new driveway - NDNs driveway has not been rendered unuseable etc. The degradation is very visible but is still in a condition in which it can be used.
Ergo, there is very little legal basis upon which the NDN can or could hold the OP liable. If it never rained, would the NDN have known or complained?
Similarly, a badly laid tarmac drive or an ageing tarmac drive can be severely impacted by years of rain on it - and its evident from the pics that the NDNs driveway is already poor - attributing that to the OP's work is a stretch and a half.