Answer
This is an official answer by QuranicNames.com Staff
There is no Arabic word like Nushaib-, and some people turn "s" into "sh" in names, for this reason Nushaiba is most likely a variant of Nusaiba like your question suggests. It is acceptable to use Nushaiba instead of Nusaiba as it is common to use non-standard variants of Arabic names as names.
