Did Dr Charles FOLD have a half sister named Velven and was his father married when he was conceived?

There is no widely available public information confirming whether Dr. Charles Fold had a half-sister named Velven or details about his father's marital status at the time of his conception. Such personal details about individuals, especially if they are not public figures, are often not documented in accessible sources. For accurate information, it would be best to consult biographical records or family histories.