the highway code recommends taking turns from the inside and outside lane, I take that as no one having right of way over the other. It's the driver 'not letting her in' who's behaviour is going against the highway code and therefore in the wrong IMO.Not saying you have to merge straight away, but if there isn't much of a queue you should. Constantly the one over the water has a couple of cars in lane and you still get dicks in the outside lane racing round to merge in at the last second and cut out 5 seconds of their time and 3-4 cars lengths. Meanwhile as they try to cut in they cause problems for the cars who are already in lane as they have to slam their breaks on as these idiots suddenly cut across the lane from nowhere.
I'm fine if they want to use the outside lane, but then they should wait to be let in. Which, if they haven't been dicks most will do.
She can use the lane as fully as she wants, but she should then wait to be let in by those in the correct lane. She does not have right of way as she is merging into another lane with cars who have the right of way.