The word ᴱQ. poroke “barn fowl” appeared in the Qenya Lexicon of the 1910s, along with a second gloss “hen” that was deleted (QL/75). In Early Qenya Word-lists of the 1920s, Tolkien glossed ᴱQ. poroke as “hen” (PE16/132). In Common Eldarin: Noun Structure from the early 1950s, Tolkien had primitive words ✶porokĭ “fowl” and ✶porokē “hen” (PE21/82). Finally, primitive onomatopoetic roots √porok or √korok “hen” appeared in marginal notes from the late 1960s (VT47/36).
Neo-Quenya: Given the above, I would retain ᴺQ. porocë for purposes of Neo-Quenya, usable both for chickens in general as well as hens, much as the default gender of the English word “chicken” is female rather than male. For a specifically female chicken, however, I would use ᴺQ. holyë “hen”. The word porocë “fowl” might also apply to domesticated birds in general.
The word ᴱQ. oi “bird, hen” appeared in the Qenya Lexicon of the 1910s under the unglossed early root ᴱ√OHO, but Tolkien considered transferring this and related words to ᴱ√OHO “cry” (QL/69). This word also seems to have appeared in an inflected form oïkta in the very early Narqelion poem.
Conceptual Development: In Early Qenya Word-lists of the 1920s, Tolkien had ᴱQ. oi and oiwe “bird” (PE16/132), forms that later developed into Q. aiwë “bird”. However, many years later in Common Eldarin: Noun Structure from the early 1950s Tolkien had the primitive word ✶kholjē “hen” derived from the root √KHOL “crow, cry aloud”, which seems to be a later iteration of the early oi “hen” word.
Neo-Quenya: Based on ✶kholjē, Gábor Lőrinczi proposed a neologism ᴺQ. holyë “hen” as recorded in the VQP (VQP). I would treat holyë “hen” as exclusively feminine, as opposed to ᴺQ. porocë which can be used both of hens and of chickens generally.