The word נַעֲרָה na'arah (girl, maiden, young lady) is almost uniformly spelled in the Torah in the form נַעֲרָ, without the concluding heh.
However, it seem that it is marked as an instance of keri uketiv only in some places, but not in others.
For example, the Leningrad Codex has Devarim 22:15 (emphasis mine):
וְלָקַ֛ח אֲבִ֥י הנער הַֽנַּעֲרָ֖ה וְאִמָּ֑הּ וְהוֹצִ֜יאוּ אֶת־בְּתוּלֵ֧י הנער הַֽנַּעֲרָ֛ה אֶל־זִקְנֵ֥י הָעִ֖יר הַשָּֽׁעְרָה׃
marked as keri uketiv (along with other instances of the word in that and subsequent passages). (See here for a facsimile of the relevant page in the codex.)
However, when it comes to Bereishit 24:16 (and subsequent instances in that passage) we find (emphasis mine):
וְהַֽנַּעֲרָ֗ טֹבַ֤ת מַרְאֶה֙ מְאֹ֔ד בְּתוּלָ֕ה וְאִ֖ישׁ לֹ֣א יְדָעָ֑הּ וַתֵּ֣רֶד הָעַ֔יְנָה וַתְּמַלֵּ֥א כַדָּ֖הּ וַתָּֽעַל׃
without an indication that this is keri uketiv, even though the word is written and read the same as in Devarim. (See here for a facsimile of the relevant page in the codex.)
What is the reason for this discrepancy?
