A root in The Etymologies of the 1930s, initially glossed “daughter” but later “child” with derivatives ᴹQ. selde, ᴹQ. seldo, ᴹQ. selda = female, male and neuter “child” (Ety/SEL-D). In Notes on Names (NN) from 1957 Tolkien gave sel-de “daughter” (PE17/170), while S. sel(l) = “daughter” appeared in both the King’s Letter from the late 1940s (SD/129) as well as the Túrin Wrapper from the 1950s (VT50/5). The diminutive form for “daughter” appeared as Q. selyë in notes from the late 1960s (VT47/10).
Neo-Eldarin: For purposes of Neo-Eldarin, I prefer √YEL for “daughter” as a variant of ᴹ√SEL(D) under the influence of √YON “son”, mostly so I can still use the 1930s “child” words for other genders, at least in the Quenya branch. I would still use Q. seldë and S. sell for “daughter”, however, with a bit of semantic drift, with “girl” words becoming Q. nettë and S. neth.
A root in The Etymologies of the 1930s glossed “day” with various derivatives like ᴹQ. are, N. aur “day” and ᴹQ. arin “morning” (Ety/AR¹). In Tolkien’s later writings, the Quenya word for “day” became aurë (RC/727; S/190), and in 1957 Quenya Notes he devised a new etymology for these day-words from the root √UR “heat” as in ✶auri “heat, period of sun” (PE17/148). That opens the question whether the various 1930s Quenya “morning” words from ᴹ√AR remain valid, but many Neo-Quenya writers (including me) retain them since there aren’t really any good alternatives. They might be salvageable as derivatives of the later root √AS “warmth” (so that “day” = “hot” and “morning” = “warm”).