Jean Carnahan was not on the ballot in the 2000 election. Her husband's name was. People voted him in (illegally) and then the Dim governor appointed her to fill her late husband's seat. I assume she has to stand for election on her own in the next cycle, which would be 2002.
And if you can vote in a dead guy, with the understanding that his wife will "fill the bill," then how come she doesn't do so for the full 6 year term? Why not just send the dead guy? Like anyone in the Senate would notice -- prop him up in the Senate, next to Byrd, Biden, Lott, and the rest, and proceed as "Weekend at Bernies?"