Word for someone who has never experienced hardship

Privileged generally means the person was brought up well educated, well fed, etc. However, it doesn't explicitly mean that person hasn't suffered hardship. A privileged person can still suffer hardship.

Sheltered is used to describe somebody who has been protected from the some of the hardships of life (such unpleasant people, or unemployment, and can also mean moral pitfalls such as drugs or 'immoral tv'.). The term also has connotations that the person's life is constrained by this sheltering (eg. restricted social opportunities, lack of autonomy in choosing one's life direction).

Consider also:

Overprotected, shielded [from life's hardships], insulated, cocooned, chaperoned, nannied.

As for a corresponding noun, one I can think of is delicate flower.

There's a colloquialism for it too. Born with a silver spoon in their mouth. I've heard it shortened to two words, just calling someone a silver spoon, or.

Here's some etymology from Wiki:

Before the place setting became popular around 1700, people brought their own spoons to the table, carrying them in the same way that people today carry wallet and keys. In pre-modern times, ownership of a silver spoon was an indication of social class, denoting membership in the land-owning classes. In the Middle Ages, when farmers and craftsmen worked long hours and frequently got dirt under their fingernails, it was important to not be mistaken for a serf or escaped slave. Under these circumstances, a silver spoon served the functional equivalent of passport, driving licence, and credit card. Since most members of the land-owning classes were smallhold farmers and craftsmen, the silver spoon was primarily a lower-middle-class cultural marker.

Lived a charmed life.
Here is the definition according to dictionary.com, they have not encountered hardship due to extreme good luck.
Charmed Life: An existence that seems protected by extreme good luck, as in Robert came out of that accident without a scratch; he must lead a charmed life .