No, it didn't seem to me that Rinny was trying to deceive the protagonist, starting with their introduction, of course. In fact, she seemed like the most sympathetic character in the game to me. And while the adventure in the succubus prison didn't have a sequel that would allow you to accompany her during her audience with the queen, it seemed to me that the bad ending that followed was simply the result of brainwashing or something like that.
But when the sequel appeared, a chain of events involuntarily arose: 1) Rinny persuades the protagonist to stay in prison; 2) having received a refusal, she is very upset, but seems to agree to assist in the escape; 3) after an unsuccessful battle with the queen and turning into a true succubus, she is already openly trying to deceive the protagonist, saying "everything will be fine, you don't need to worry, I will do everything" - and in fact, her goal is to leave her friend in prison forever; 4) after waking up from the dream, Rinny says that she invited the protagonist to an audience with the queen only because she was afraid to go alone (that is, not at all to help the protagonist escape from prison).
You see, Mistira is hostile and dangerous, but if she promises something, she does it. Marin, although she has reasons to be offended by the protagonist, always knows where to stop in her "revenge". And Rinny - it just so happened - shows treachery and a complete lack of empathy. She herself was just captured by Edith, and she did not like it there - why does she not understand that her friend can feel the same?
But be that as it may, I do not want to impose my opinion. The game has the main thing - it maintains intrigue, there are mysteries that you want to solve - from the origin of the protagonist to the closed door in the horror shop. And this episode, in the end, can be explained by some kind of clouding of Rinny's mind, especially since she then returns to her usual behavior.