A word appearing in several sets of notes from the late 1960s having to do with Hands, Fingers and Numerals. It was related to the finger name of the fourth finger (representing the sister). Tolkien mostly glossed it either as “(little) girl” or “sister (diminutive)”, but in one placed indicated it originally meant “pretty little thing” (VT47/33) and in another that it might be used for “daughter” (VT47/15). He also gave it several derivations, from √NET “trim, pretty, dainty” (VT47/33) or the root √NETH which itself was given a variety of meanings: “sister” (VT47/12, 26, 34), “(young) woman” (VT47/15, 32, 39) or “fresh, lively, merry” (VT47/32).
Neo-Quenya: For purposes of Neo-Quenya, I think the meaning “(little) girl” is the most useful. For “sister” I would use nésa.
nettë (stem *netti-, given the primitive form listed in VT47:17) noun "girl, daughter" (but also "sister", see below), also used as a play-name of the "fourth finger" or "fourth toe" (VT47:10, VT48:6), in two-hand play also used for the numeral "nine" (nettë is conceived as being related to nertë, q.v.) Nettë is also defined as "sister" or "girl approaching the adult" (VT47:16, VT49:25), "girl/daughter" (VT47:15-16); it may be that "sister" was Tolkien's final decision on the meaning (VT48:4, 22) - The related word nésa seems like a less ambiguous translation of "sister".