In his classic work of historical fiction, A Tale of Two Cities, Charles Dickens suggests that family members of those sentenced to death by the various tribunals were themselves targeted for execution, if for no other reason than kinship.
To what degree was extending punishments to familial relations who would not have been indicted otherwise practiced during the French Revolution? What was the extent in numerical terms, supposing such data are available from the records of the condemned?
The only thing you needed to be sentenced to death in the Great Terror was to be found as an "Enemy of the People". This doesn't provide a lot of restriction that would spare relatives of another Enemy, and their supposed hostility might provide reason to declare them an Enemy in turn.
Certainly the King and Queen were both executed when their time came.
From Google Answers:
In "Le Quid" (famous french encyclopedy) they wrote about a book called "histoire générale et impartiale de la révolution" written in 1797, that stated 2567 women were killed by guillotine (the book wrote that 18613 people were killed by guillotine during the Revolution)
The 2567 are : - 750 women - 1467 married to a farmer or handworker - 350 religious women ("religieuses")
Strange categories but in 1797 they probably used different social categories than now.