For Nabiha please see this answer: Nabiha, Nabih, Nabeh and Nabeha Details
As for Najiha, pronounced as (NU)mber + (J)oy + sw(EE)t + (HU)mble, is a non-Quranic name for girls that means "successful", "competent", "productive". It is an Arabic name but it doesn't come from the Quran. Since the meaning is good Muslims can use it. It can also be spelled as Najeeha, Nejeehe, Nejihe, Najihah, Najeehah.
Najiha also has a version for boys, Najih, pronounced as (NU)mber + (J)oy + sw(EE)t + (H)umble. It is non-Quranic and has the same meaning as Najiha. It can also be spelled as Najeeh, Najihe, Nejih.