During the week before her funeral, which was going to take place on the last shopping Saturday before most children went back to school, I asked many, many people in the ordinary suburb I was living in what they thought about it all. Not a single one of them was in the least interested in her as a person, none thought she had been deliberately killed, none grieved her much ("It's a shame she died so young" was common, but "her poor boys" was far more a concern) and almost all were exasperated about the timing, which was monstrously inconvenient for them: buying last-minute things for their children's new term had been made extremely difficult because the shops were all going to be shut. And the shopkeepers, most of whom I knew well, didn't feel the slightest respect for her; they planned to close on that day because they were afraid people would think they weren't being respectful after someone had delivered a leaflet about it all along the street. Some of them thought that if they were open they might get a brick though the window from a nutter. All knew that they would lose the money for that day because of her and were not bet pleased by that.
One of the people I talked with described the whole press furore as "they want the whole county to come down with DI-arroeah and dribble about her all over the street".
I did know one person who cancelled a weekend in Paris, but when I asked her why, she didn't really know: it wasn't because she had liked Diana (she was clear on that) but a sort of incoherent fear that They might have it in for Brits in some way and it would all be rather awkward. Or bad luck, or something.
The jokes about her death had begun to circulate on the internet within a very few hours of the news being announced; my favourite was the Australian site which had "Latest news about Diana" on the front page, and when you clicked on it the page you were sent to simply said "Yup, still dead." Most of the others were cruel and taking the piss of both her and Dodi. Not a lot of love there! And I was sent them by people all over the country.
I would say that she was certainly well-known, possibly even notorious, but I am not at all convinced she was popular; more a focus for people's catharsis. Many now have no idea why they felt anything at all about her after the immediate shock, or why they went to put flowers outside the house she'd lived in to rot and smell vile for streets in all directions.