she is the (yet to be named) daughter of the most badass overlord in the entire cosmos (she'll get an extra story once the phantom kingdom remake is out named "my father is the strongest overlord")
According to Gpara & dengeki, her name is ペタ (Peta). Since she claims to be Zetta's daughter, I'm not sure if we want to have her tag be Peta (straight transliteration) or Petta (presumed official English name if it ever gets translated).
how about that: scince zetta and peta are terms that are used to discribe really really large numbers (zetta = Trilliard; peta = Billiard) Peta would be fitting so to say: Zetta is a large Number