A root implied by various Quenya words having to do with “judgement” from the 1950s and 60s, most notably Q. Námo “Ordainer, Judge” as the true name of Q. Mandos (S/28), a name that began to appear in documents starting in the early 1950s (PE21/85). The root is evident in other words from this period, such as Q. namna “statute” (MR/258), Q. námië “a single judgment or desire” (VT41/13) and the verb Q. nam- “judge” in the phrase: Q. ore nin karitas nō namin alasaila “I feel moved to do so but judge it unwise” (VT41/13). ✱√NAM might also be the basis for the second element of the name Q. Rithil-Anamo “Doom-ring”, the circle of thrones where the Valar sat in council (WJ/401).
In notes from 1969 Tolkien seems to have changed his mind of the root for “judge”, writing Q. nemin >> Q. hamin >> Q. navin for “I judge”, and giving a new root √NDAB “to judge” in a marginal note along with a revised name Návo to replace Námo (PE22/154, notes #53 and #55). This new root conflicts with √NDAB “endeavor, try” from earlier in the same bundle of documents (PE22/151).
Neo-Eldarin: For purposes of Neo-Eldarin, I would ignore the late change of ✱√NAM >> √NDAB “judge”, since ✱√NAM has more attested derivatives and Námo appears in the published Silmarillion. Also, all of the derivatives of this root are Quenya, and its possible use in the name Rithil-Anamo (coined in Valinor) imply that it might be a root invented after the Elves arrived in Aman. Thus I think it is best to treat it as Quenya-only root, and used ᴹ√BAD “judge” as the basis for (Neo) Sindarin words for judgement by retaining Noldorin words with these meanings from the 1930s (Ety/BAD).
For most of Tolkien’s life, the Primitive Elvish root for “mother” was √AM. This began with the Qenya Lexicon of the 1910s, where Tolkien gave the root as ᴱ√AMA (QL/30). In The Etymologies of the 1930s it was ᴹ√AM with derivatives ᴹQ. amil and (archaic) N. emil “mother” (Ety/AM¹). In Quenya prayers of the 1950s, the word for mother was Q. Amille. In the last few years of his life, however, Tolkien toyed with the notion of changing this root to √EM. In notes associated with Eldarinwe Leperi are Notessi written in the late 1960s, Tolkien first gave the root as am, but then wrote em next to it with a question mark, along with several new em-derivatives (VT48/19 note #16). The Q. affectionate word emme for “mommy” appeared in the main article, indicating Tolkien did, in fact, adopt this new root, at least for some period of time.
Neo-Eldarin: For purposes of Neo-Quenya writing, I personally prefer to ignore this late change to the root for “mother” and stick with the √AM-forms Tolkien used for most of his life. However, the √AM-forms were less stable in the Sindarin branch of the languages, so I’d use √EM-forms like S. emel and emig, and would assume √AM and √EM were variants of the root, as they were on VT48/19 (see above).