Okay, since no one else has commented, I guess I'll post a mini review for anyone who is interested.
This manga isn't really about the MC, it's about her older sister and her girlfriend and some issues they are having with their relationship. Also, it's a weirdly casual way for someone to come out to a sibling. "Oh, can me and my girlfriend come over and stay at your place?"
It isn't very long, and it definitely deserves the drama tag, but I think it should include the slice of life tag, as the story is pretty much just a small segment of these three character's lives. There's a decent kissing scene and some nice romance to go along with the drama for you other yuri fans.