It's probably either Semyonovna or Symonovna and it means 'daughter of
Semyon (or
Symon)'. Russians and Ukrainians don't have a middle name in the western European sense. Instead, they have a patronymic name that is derived from the name of their father -- in this case,
Semyon or
Symon.
~ Ivayla,
skillfully disguised as a responsible adult