It is uncertain whether ⲥⲉⲙⲛⲓ should be understood here as the genitive of the anthroponym Sem in the function of patronymic ('daughter of Sem', thus Ruffini in P. QI 4 72), or a toponym belonging to the designation of an office ('as of Semna', thus Łajtar – Ochała 2015).
The name may be a derivative of Simeon, but its exact formation is unknown to me.
Inspiration: probably one of New Testament figures, Apostle Simon Peter, Simon the Zealot, or Simon, brother of Jesus.