Slovene nun?

My g-g-grandfather, Michael Paulin, was born in Slovenia in 1880.I've seen several different locations offered as his hometown/place of birth, including "Litija" and "Podper." ("Podper" doesn't seem to be a place, so I'm not sure if that's Podpec or Podborska, or what.)

He had a sister, Sophie, who remained in Slovenia and was a nun.I'm not familiar with the Catholic church, but I would think there would be records somewhere of nuns, wouldn't there?How would I find out where she was, or if there was a convent near Litija or something?