>*k:al-axwa "female-in-law" consisting of *axwa
> "brother" and *k:al-, presumably "woman".
Isn't that the sort of "compounding" that you find in Semitic? "word-God"
(accent producing a reduction in vocalism of the first element to what is
called a "construct" form) = "word of God". So here, "woman-of brother".