The root of "daye" for "mother" in kurdish and zazaish goes to old iranic:
- dā- = verb-root for "lactation" in Old Iranian (if a mother lactate his baby)
- "daēnu-" was in Avestan "lactating"
Source: Mirzali Zazaoglu of the Zazaki Institue (his source: University Frankfurt)
The word "baran" - in middle persian 'vârân', Zazaish 'varan', Mazandarani "varish", - comes from old iranic 'vâr' which meaned "water" and had the same root as english "water". in avesta was 'vâra' = rain. 'vârantî' = if it rains.
Source:
http://www.kurdica.com/News-sid-Baran-162.html
Baran Ruciyar, his source (books):
"Bartholomea, Indogermanische Forschungen I, 178"
vgl. P. Horn, Grundriss der neupersischen Etymologie, Strassburg 1892, "bâran"