On the other hand, she is qualified to perform the actual duties of a senator. Let's look at those:

Senators bloviate on anything and everything, regardless of whether they know what they are talking about. This is an important part of the job. Senators must sound as though they know how to create jobs, what kind of energy the United States should use, how to make health care affordable, how to plan education for 75 million unique children, and so on. They don't have to actually know how to do these things. They just have to sound as though they know. I know very little about Caroline Kennedy, but I'm sure she's capable of making pronouncements about how progressive polices will save the world.

Another thing senators do is cast votes to spend other people's money. Caroline Kennedy should be very good at that. She grew up in a wealthy family. Her stepfather was one of the richest men in the world. Now she's married to a wealthy businessman. She's had lots of practice spending other people's money. She'd be good at it.

All this is not to say the job of a senator is easy. Senators do have to figure out which interest groups to reward with subsidies, special tax breaks and pork in order to assure reelection. But with a little work, that's probably not hard to learn.

So by the standard of the actual duties of a U.S. senator, Caroline Kennedy is eminently qualified.

But, of course, so is virtually everyone else.