I am a solicitor with over 15 years experience. I will try to help you with this.
I do not think you are being unreasonable at all. Am I right in thinking that the plans as approved do not mention what will be put in to restore the right of way? Was there something in the original plans and the permission about the right of way at all and if so what?
hi. there was only a proposed change of route indicated on the original plans which I saw, but the design was changed at a later date. there was no indication of what this might entail. The subject of the right of way did not seem to be considered, and in principle I did not object to a change, but there was no agreement before the plans were passed and I commented on this before the permission was granted when there was reference to there being no loss of facility to other detached neighbours but not to myself. Loss of a suitable path would constitute to a loss of facility to me.
I think you need to try and find out what the plans are again. If she is not forthcoming and the work is imminent you will not practically be able to do anything except to watch what she is doing and if it seems wrong to tell her immediately. You would be able to take action if she puts in a path that is no any use to you and it might be worth reminding her of this at this point and suggesting that a good deal of potential trouble could be avoided by talking to you at this stage. If she ignores you and puts in a path that is not satisfactory you will have to take action after the event.