Where does “Ivona” come from?

Ivona (Slovak) comes from French Yvonne, from French Yves, from Proto-Celtic īwos, from Proto-Indo-European *h₁eyHw-.

Ancestry of “Ivona”, step by step

Step	Language	Word	Meaning
1	French	Yvonne	—
2	French	Yves	—
3	Proto-Celtic	īwos	yew
4	Proto-Indo-European	*h₁eyHw-	—