Where does “Ільїна” come from?

Ільїна (Ukrainian) comes from Ukrainian -їна́, from Ukrainian -ї́н, from Old East Slavic -инъ, from Proto-Slavic -inъ, from Proto-Indo-European -iHnos, from Proto-Indo-European -no- — adjectival suffix.

Ancestry of “Ільїна”, step by step

Step	Language	Word	Meaning
1	Ukrainian	-їна́	—
2	Ukrainian	-ї́н	—
3	Old East Slavic	-инъ	—
4	Proto-Slavic	-inъ	-ine; Creates singulatives, mostly with...
5	Proto-Indo-European	-iHnos	Creates adjectives of materials
6	Proto-Indo-European	-no-	adjectival suffix

Every word from Proto-Indo-European -no- →Every word from Proto-Indo-European -iHnos →Every word from Proto-Slavic -inъ →