Well, the dictionary showed me холостячка

Babylon Rus-Eng
холостячка (f)
n. single woman, bachelorette, unmarried woman

Efremova (Russian Explanatory Dictionary)

холостячка
холостячка
ж. разг.-сниж.
Женщина, которая не состоит в браке; незамужняя женщина


But I guess it's not in common use? Anywho, thank you guys, I'll fix it. Good to know!