What happens when all players land on licorice in Candy Land?
In games in general, if all players skip a turn, that is the equivalent as doing nothing.  You fast forward through all skipped turns, and the game picks up as if none of those players had skipped a turn.  The reason for this is that the turn still happens in a metaphysical sense, but ends as soon as it begins.
In this case, it goes like this:

Your wife ends her turn.  Turns remaining to be skipped: son 1, wife 1.
It is your son's turn: that turn is skipped.  Turns remaining to be skipped: son 0, wife 1.
It is your wife's turn: that turn is skipped.  Turns remaining to be skipped: son 0, wife 0.
It is your son's turn.

Note that in games where players can miss multiple turns consecutively (this is likely not relevant to Candyland), you can only shortcut through the least number of pending skipped turns by any player.  So if you have two players in a game, and player A would skip 3 turns and player B would skip 2 turns, this is the same as Player A skipping 1 turn.