A doubtful word according to Tolkien's later conception; in the branch of Eldarin that Nandorin belongs to, primitive KW became P far back in Elvish linguistic history [WJ:375 cf. 407 note 5]. This was not a problem in Tolkien's earlier conception, in which the Danians came from the host of the Noldor, not the Teleri [see PM:76; the idea of the Nandor being of Noldorin origin also occurs in VT47:29]. In his later version of Nandorin, the word cwenda is probably best ignored; simply emending it to *penda would produce a clash with primitive pendâ "sloping" [cf. WJ:375].
In the Etymologies, Tolkien derived cwenda from kwenedê "elf" (stem KWEN(ED) of similar meaning, LR:366; as for the shift of original final -ê to Nandorin -â, compare hrassa "precipice" from khrassê). But later the primitive word that yielded Quenya Quende was reconstructed as kwende (WJ:360).
No certain example shows how original short final -e comes out in Nandorin, so we cannot say whether kwende is also capable of yielding cwenda, ignoring the question of kw failing to become p.
Note: "The Galadrim were 'Tree-people' (though the formation is Sindarin, + S [rim] = Q rimbë, great number) = true Sindarin galadhrim."