Yep, sounds weird for me as well. We have separate words for boyfriend and girlfriend, but those have a kinda deeper meaning*, using "girl" and "friend" to describe someone who's really close to me is extremely weird. Like, the days she could be called a "girl" are in the past and calling her the same term as I call for example my work friends is just weird. So in my language I do use the equivalent of "boyfriend" and "girlfriend", but almost never in English.

* The word comes from a word for close friend and nowadays basically isn't used to mean "friend" anymore. I mean, it still does, but no one uses it that way. And even then it signifies some deeper connection between people compared to our more common word for "friend".