Her name in the original Italian version was and still is: Aisha. Nick didn't change anything. 4kids was the only version which altered her name. (To Layla, of course)
I have no idea why they changed Aisha's name to Layla. In the original version, her real name is Aisha. Only Nick kept her real name. All the other shows changed it to Layla. I don't know why they changed it to Layla. I think it should be Aisha because it sounds tougher than Layla.
Her name was never Layla.In the original it was Aisha.But the 4kids TV dubbed it.They wanted it to be más american so they changed the name to Layla. 4kids made too many changes so they lost Winx Club.So Nick took over.They teamed up with arco iris and gave Aisha her rightful name.
Because sometimes in japón it'd be actually "Leila" possibly, but I have no idea Aisha o Layla would be actually original Italian name, "アイシャ" (Aisha) and "レイラ" (Reira) are two Japanese names of Aisha, but "アイシャ" (Aisha) is just Aisha, and "レイラ" (Reira) is both Leila and Layla, so Leila in Japanese means "レイラ" (Reira), the possible Japanese name of Aisha, beyond "アイシャ" (Aisha). Beyond that, the Japanese name "アイシャ" (Aisha) is similar to Japanese name "アイシー" (Aishī), Icy's Japanese name, Icy in Japanese means "アイシー" (Aishī), Aisha and Icy have very similar Japanese names, here is Aisha in the "casual" from "Winx Club: World of Winx".