Not sure if she just uses “Slavic name” instead of Bulgarian name. She probably doesn’t know but most names are not Slavic so I will assume she means a Bulgarian traditional name instead-Ivana, Irina, Irena, Anelia, Albena, Ivayla, Lillya, Maria, Sofia, Elena, Raya, Siyana, Diana, Yoana, Simona, Darya- these are popular in Bulgaria
Popular Slavic names -Radoslava (female version of her bf’s friend), Radost, Dobromira, Krasimira, Miroslava, Desislava, Vladimira, Vladislava, Borislava, Svetlana, Lyubomira, Stanislava, Svetoslava and many more.
I doubt that she meant Slavic name, she probably means Bulgarian name in general