I think the situation is obviously quite different for born Royal females than for those who 'marry in'. Born royals (whether male or female) become used to staring strangers, limited opportunities to go shopping, to the cinema etc without a lot of fuss being made, and to photographers.
For those newly married to Crown Princes, senior royals etc the pressure must be dreadful. In addition to mastering the protocol and looking dignified, cheerful and interested when in public you have everyone from journalists and fashion editors to anonymous commentators on the Internet commenting on your clothing, hair and makeup. In general you have to wear clothes from your country's designers solely, too.
Of course born royals get this as well, but they do have a lifetime to get used to it and if they are women who, like the Queen, aren't particularly interested in fashion, then the public tends to accept that, not that comments cease! I would hate it, but then I like the casual look and don't like daily makeup or wearing high heels.