What did she demand?
Yes, I was wondering that too.
People keep alluding to "bratty behaviour" (such as?) and "demands" but never actually say what she's supposed to have done.
A visit had been arranged to a market in Fiji where M was supposed to meet and chat to stallholders, who were mainly women (and who were excitedly waiting to meet her -it was a big deal for them). M entered the market but very quickly, her mood changed and she ignored the stallholders etc and demanded to be got out of the market immediately. If you watch the film of it, you can see the moment that she says something very tart to an aide and the poor woman looks super-stressed.
Apparently, what happened was: several women from the UN were there and approached M. It was at this point that she panicked and demanded the visit to be jettisoned (PR and diplomatic nightmare, as well as very mean to the ladies in the market) and this is likely to be because she was furious that the UN had rejected her application to become an ambassador (as Emma Watson is). EW had also snubbed M when M asked to meet her about this very subject, and Meghan was said to be hyper-sensitive about the matter.
You can see these blue-t-shirted UN women trying to make contact with her in the market and it's at that point that she freaks out and runs away. The story was put out that M, being pregnant, was too hot/feeling faint. Who am I to say that's not at least partly true? But watch the film of this incident, and you'll see there's a lot more to it than that.
The tall, blonde security woman was later seen sobbing in her car. And you can see she's on the verge of tears in the market. Before anyone says she's a wimp (as implied in another post) please consider that this might have been the final straw which broke the camel's back.