Paulina is also Croatian and Hungarian, used alongside Paula in Croatia and Hungary. The name day for Paulina in Croatia is August 31. The name day for Paulina in Hungary is June 22.
I have met several women from Poland, especially Krakow, who have this name. Each of them tells me, all women in Poland are named "Paulina." Looking at the list, it appears to be overwhelmingly more popular in Poland than elsewhere.
https://www.beliebte-vornamen.de/10269-paulina.htm
https://www.behindthename.com/name/paulina/top/austria
https://www.behindthename.com/name/paulina/top/germany-berlin
https://en.m.wiktionary.org/wiki/Paulina#German
https://de.m.wikipedia.org/wiki/Pauline#Varianten - listed as a variant