For some photographers, they would prefer to retain some/most rights in the images, and hence you have some who disagree with the lady's intentions. These photographers may see such a shoot as potentially valuable to their portfolio.
For some other photographers, they may totally relinquish their rights in the images with a hefty fee. This is possibly quite common, especially in the commercial world when they are hired by a client to create images, and the client doesn't want the photographer using the images elsewhere.
I'm not a professional who spends most of his waking time shooting nudes but have done some in Singapore and in Australia, and keep the images for my portfolio. Personally, it's easy to see that many Singaporean women are conservative about doing nude photography (even bikinis give some the creeps), and this conservatism could make it very difficult to get aesthetically excellent images. It's really my preference to meet up with the model/client (such as this lady) to ice-break and discuss issues regarding the photography whether posing nude or clothed.
I hate to say this, but there will be misbehaving men everywhere although it appears that S'porean men are quite notorious (judging by news reports). Blame it on deprivity or whatever you want to think it might be.
In Australia, women may sunbathe topless on a public beach with men around her but nobody gives a hoot. Yes, the men may look and get excited but they don't appear to behave in the same way as S'porean men. (Sorry I don't mean any deliberate offence but this is my true real-life observation.) Breasts, cleavage, or whatever you wanna call it, under a bikini or low-cut top, are a normal everyday sight in their lives for years. Some Aussie women aren't afraid to show, and there are plenty of bare bosoms in all kinds of books/magazines in the land down under.
I would agree with the ClubSnap member who mentioned Playboy magazine. Possibly unseen by, and unknown to, many S'poreans, especially the women who shun this publication, Playboy demonstrates some magnificent photography. The images are provocative but not porn-ish. In fact, Playboy is NOT a porn magazine, it's a men's magazine, like FHM or Maxim but features nudity. I also agree with that member that the first shoot may be a bummer, and images on subsequent shoots after being comfortable in the nude, tend to be better. I know this from personal experience doing shoots with models clothed or nude.
I strongly agree with 1 ClubSnap member who said that if there isn't any trust with the photographer, there's really no point doing the shoot, paid or not, rights retained or not, chaperoned or not. I would also add that if the lady is uncomfortable in the nude, don't bother posing nude. You have a psychological barrier/hindrance. No matter how good the photographer is, your nudity will eventually eat you. Don't follow others (whom you might have seen/heard of) who have posed nude just because you think it may be cool.