Zyva is the Persian pronunciation of Ziwa, which refers to the Sabian concept for "light" (opposite of darkness), "good" (opposite of evil). Sabians are a rightly guided religious group whose last prophet is Prophet Yahya, and who are mentioned in the Quran as good believers who will enter Paradise.
Since Zyva/Ziwa has a good meaning, Muslims can use, though some scholars would recommend using Muslims names, since we have enough good Muslim names and there is no need to use names from other religions, but ultimately it is your own personal choice since Islam allows it. Zyva is pronounced [(Z)oom + sw(EE)t] + [(VA)st], with emphasis on the second syllable. Zyva can also be written as Zeeva, Ziva, Zeva, Zeyva, Zivaa, Zyvaa. It can also be pronounced with a w instead of a v, as in Ziwa, Ziwaa, Zeewa, Zeywa.
Zehra is the Persian pronunciation of Zahraa. It is a good name and you can use it, either as Zehra or Zahraa. For more information on this name see: Zahraa