They really try to avoid spelling the word lesbian
late, but you mean "So i am like that".
Honestly i think that just simple there are no word equal in Japanese ? i check translate and the japanese word just loan words of the "lesbian". I think it just make sense that the character don't know any other word to describe that yet. Which feel like make totally sense to me.
What else is the reason ? this is straight up explict yuri, dont see any reason author would adraid of using a english words. and also they use the world Yuri