From the Catholic Encyclopedia:
Catholics with very few exceptions accept the book of Judith as a narrative of facts, not as an allegory. Even Jahn considers that the genealogy of Judith is inexplicable on the hypothesis that the story is a mere fiction (“Introductio”, Vienna, 1814, p. 461). Why carry out the genealogy of a fictitious person through fifteen generations? The Fathers have ever looked upon the book as historical. St. Jerome, who excluded Judith from the Canon, nonetheless accepted the person of the valiant woman as historical (Ep. lxv, 1).
Against this traditional view there are, it must be confessed, very serious difficulties, due, as Calmet insists, to the doubtful and disputed condition of the text. The historical and geographical statements in the book, as we now have it, are difficult to understand: thus
[The article goes on to list several perceived errors in Judith]
These are serious difficulties, and a Catholic student must be prepared to meet them. There are two ways of doing so.
(a) According to what we may term “conservative” criticism, these apparent difficulties can every one be harmonized with the view that the book is perfectly historical and deals with facts which actually took place. Thus, the geographical errors may be ascribed to the translators of the original text or to copyists living long after the book was composed, and consequently ignorant of the details referred to. Calmet insists that the Biblical Nabuchodonosor is meant, while in Arphaxad he sees Phraortes whose name, as Vigoroux (Les Livres Saints et La Critique Rationaliste, iv, 4th ed.) shows, could easily have been thus perverted.
Vigoroux, however, in accordance with recent Assyrian discoveries, identifies Nabuchodonosor with Assur-bani-pal, the contemporary of Phraortes. This enables him to refer the events to the time of the captivity of Manasses under Assur-bani-pal (2 Chronicles 33:11; cf. Sayce, “Higher Criticism and the Verdict of the Monuments”, 4th ed., p. 458). It is further maintained that the campaign conducted by Holofernes is well illustrated in the records of Assur-bani-pal which have come down to us. And these facts will undoubtedly afford an explanation of the apparent allusion to the captivity; it was indeed a Restoration, but that of Manasses, not that under Esdras. The reference, too, to the Sanhedrin is doubtful; the term gerousia is used of the “ancients” in Lev., ix, 3, etc. Lastly, Conder’s identification of Bethulia with Mithilia (loc. cit. supra) is highly probable. Moreover, the writer who described the strategical position in iv, 1-6, knew the geography of Palestine thoroughly. And we are given details about the death of Judith’s husband which (viii, 2-4) can hardly be attributed to art, but are rather indications that Judith represents a really existing heroine. With regard to the state of the text it should be noted that the extraordinary variants presented in the various versions are themselves a proof that the versions were derived from a copy dating from a period long antecedent to the time of its translators (cf. Calmet, “Introd. in Lib. Judith”).
(b) Some few Catholic writers are not satisfied with Calmet’s solution of the difficulties of the Book of Judith; they deem the errors of translators and of scribes to be no sufficient explanation in this matter. These few Catholics, together with the non-Catholics that do not care to throw the book over entirely into the realm of fiction, assure us that the Book of Judith has a solid historical foundation. Judith is no mythical personage, she and her heroic deed lived in the memory of the people; but the difficulties enumerated above seem to show that the story as we now have it was committed to writing at a period long subsequent to the facts. The history, so it is maintained, is vague; the style of composition, the speeches, etc., remind us of the Books of Machabees. A remarkable knowledge of the Psalter is evinced (cf. 7:19 and Psalm 105:6; 7:21, and Psalm 78:10, 93:2; 9:6, 9, and Psalm 19:8; 9:16, and Psalm 146:10; 13:21, and Psalm 105:1). Some of these psalms must almost certainly be referred to the period of the Second Temple. Again, the High Priest Joachim must presumably be identified with the father of Eliashib, and must therefore have lived in the time of Artaxerxes the Great (464-424 B.C. Cf. Josephus, “Antiquities”, XI, vi-vii). We referred above to a shorter Hebrew version of the book; Dr. Gaster, its discoverer, assigns this manuscript to the tenth or eleventh century A.D. (Proceedings of Soc. of Bibl. Archaeol., XVI, pp. 156 sqq.). It is exceedingly brief, some forty lines, and gives us only the gist of the story. Yet it seems to offer a solution to many of the difficulties suggested above. Thus Holofernes, Bethulia, and Achior, all disappear; there is a very natural explanation of the purification in xii, 7; and, most noticeable of all, the enemy is no longer an Assyrian, but Seleucus, and his attack is on Jerusalem, not on Bethulia.
If it could be maintained that we have in this manuscript the story in its original form, and that our canonical book is an amplification of it, we should then be in a position to explain the existence of the numerous divergent versions. The mention of Seleucus brings us down to Machabean times, the title of Judith, now no longer the “widow” but the “virgin”, may explain the mysterious city; the Machabean colouring of the story becomes intelligible, and the theme is the efficacy of prayer (cf. 6:14-21; 7:4; 2 Maccabees 15:12-16).
Full article: newadvent.org/cathen/08554a.htm