Known members are siblings Lemony, Kit, Jacques, their grandfather, Chas. Snicket, and E. Snicket - who could either be their father, Jacob, or their mother, making it unclear whether Jacob or his wife is the one who married into the Snicket family.
They are one of the most secretive families in the series and we learn relatively little about their personal lives. Each of the known members pay a heavy price for their involvement in the Baudelaire tale.
On the original genealogy, Jacob Snicket is seemingly listed as "E." There is no explanation given for this inconsistency, although Lemony Snicket does mention that his father's bridge partner knew him by another name. There is also speculation that E. Snicket may refer instead to Jacob's wife, making him the one to have taken the surname of Snicket from her, but there has been no evidence besides Jacob's first name to suggest this.
As demonstrated by this family tree, the Snickets are named in alphabetical order (with the exception of Jacob, as discussed): ABC, DEF, GHI, JKL, MNO (and even continues with a hypothetical [PQR], [STU], [VWX], [YZA], [BCD], [EFG], [HIJ], [KLM], [NOP]).
The "G" and "I" may refer to the brothers Gregor and Isaac "Ike" Anwhistle, which would indicate the existence of a third sibling (a possible scenario, since facts concerning the Anwhistles are scattered). Within the series only three characters whose last names are unknown have first names beginning in H: Hal, who is both too old to be their sibling and not a member of V.F.D.; Hector, who is probably too young to be their sibling, and Hugo, who is too villainous. In addition, Hector gives no indication that he has any siblings or that he is familiar with Josephine Anwhistle. However, he also gives no indication that he is familiar with V.F.D. when it is discussed extensively in his presence, even though the Autobiography states that he is a member. Regardless, if "G" and "I" refer to Gregor and Ike, then "D. Snicket" is likely to be be female (for her children to be surnamed "Anwhistle"). This makes her Josephine's mother-in-law, whom Josephine describes as having only one eyebrow and one ear. Furthermore, if "G" and "I" refer to the Anwhistles, then the Snickets are distant in-laws to the Baudelaire family (to whom Josephine is related; her sibling married a second cousin of the Baudelaires and she is their "second cousin's sister-in-law" - namely the sister of the spouse of the Baudelaires' second cousin.). There is another possibility explaining why there is no "H" Snicket mentioned in the series: it could be a sister to Gregor and Ike and not a brother, which would explain why neither Hector, Hal nor Hugo are the sibling of Gregor and Ike.
The "O" may refer to Count Olaf (whom Snicket frequently calls "O" in The Unauthorized Autobiography and The Beatrice Letters). Although he is never said to have siblings, Olaf himself is very guarded about his family's past. However, as a "neophyte" in V.F.D., Lemony Snicket makes no indication in his complaints about Olaf that they are first cousins. If this "O" is, indeed, Olaf, then the Snickets are in-laws to the Baudelaire family. It is interesting to note that there is a hangman's noose on the "O" branch.
'M' and 'O' could also plausibly be Miranda and Olivia Caliban. This would definitively fit the family tree, and would reveal that they have a sibling whose name starts with an 'N'. It would mean that, like D. Snicket, F. Snicket is likely to be female to have gained the surname 'Caliban'. However, it is unconfirmed that Miranda and Olivia are even siblings at all, as 'Caliban' could be Miranda's married name (namely the surname of her husband, Thursday). There is also the argument that Miranda named her daughter Friday, deviating from the alphabetical naming rule (however, the fact that her name begins with 'F' matches both the names of Fernald and Fiona, tying in to the otherwise unrelated theory that she may be their mother as well), but as Miranda is hinted to be on the fire-starting side of the schism, this could be explained by wanting to estrange herself from her Snicket relatives, who are known to be on the fire-fighting side.
However, the "M" may also refer to Montgomery Montgomery (whom Snicket frequently calls "M" in the The Unauthorized Autobiography and The Beatrice Letters). Montgomery is known to have at least one sibling (a sister), and is not closely related to Count Olaf. If this "M" is Montgomery, then the Snickets are again in-laws to the Baudelaire family, but not closely related to Olaf. If the "M" refers to Montgomery Montgomery, then F. Snicket must still likely be female for her children to have taken Montgomery as a surname. As well as this, if the "M" refers to Montgomery Montgomery, then either "N" or "O" is the person who married the cousin of Bertrand Baudelaire; this person is also the mother-in-law of Josephine Anwhistle's sister, who married the second cousin of the Baudelaire's who was the son of his first cousin (and of either "N" or "O").
Notably, the Denouement triplets also fit in with the alphabetic naming rule of the Snickets. If Dewey is assumed to be the eldest, and Frank is assumed to be the youngest, then their names progress as 'D', 'E' and 'F'. However, the part of the Snicket family that follows the three children being named as D, E and F is confirmed to be the generation possibly including Jacob Snicket, known to be Jacques, Kit and Lemony's father, and the next generation which would include these letters would not have all three of them together for a second time; E and F would be together, but D would be in the previous trio of letters. D, E and F would therefore not be together again for around twenty-six generations. As it is fairly certain that the Denouement triplets are not part of Jacob Snicket's generation, due to both their age (the same as Jacques and Kit Snicket), surname and Dewey Denouement's assumed association with Kit, this must mean that it is either a coincidence, or that the Denouement family has a similar way of naming their offspring (perhaps even adopted from the Snickets).
- In Lemony Snicket The Unauthorized Autobiography, the index refers to the family as the Snicket Clan.
- In The Slippery Slope, when Snicket imagines about all the great things that the Baudelaires will never be able to do at the V.F.D. Headquarters, he mentions his grandmother's recipe for almond cookies (which apparently is one of his favorite foods as seen in All the Wrong Questions). Exactly which grandmother he was refering to is unknown.