The printer’s manuscript has the singular sorrow here in Ether 8:8. The 1830 typesetter accidentally copied it as the plural sorrows. The 1908 RLDS edition restored the singular (in accord with the reading in 𝓟). Although the text contains examples of both the singular and plural for this word, the singular seems correct here because the following verse again refers to the father’s sorrow: “whereby hath my father so much sorrow” (Ether 8:9). There are also other instances in the text of “sorrow of NP” (but none of “sorrows of NP”), where NP is a noun phrase:
The critical text will restore the singular sorrow here in verse 8.
Summary: Restore the singular sorrow in Ether 8:8 since it is the reading of the earliest extant text; it is also supported by the singular sorrow in the next verse.