* * Revised Fall of Gondolin pt.5 -- >end [the remaining sections] * *

[Maédhros]

From the Book of Lost Tales I: Appendix

Ónen The root ’O’O in QL has derivatives Ô, a poetic word, 'the sea', oar 'child of the sea, merchild', oaris (-ts), oarwen 'mermaid', and Ossë; the name Ówen (antecedent of Ónen in the text, pp. 59, 80) also appears, and evidently means the same as oarwen (for -wen see Urwen). The later form Uinen in the Tales is apparently Gnomish; GL Únen 'Lady of the Sea', changed later to Uinen. A form Oinen also occurs (p. 238).

I agree with you that given that because of the Qenya Lexicon (QL) it is to be considered Quenya.
It if its to be kept in Quenya then I would also agree for it to be changed to Earni.