Right. That's why Alicent brought Rhae to the gods wood cuz thats where they used to kick it when they was young.
And I don't think rhae thinks alicent is a snake who would turn on her, but just that there's no way of telling what side some information will land on for alicent. As a girl who's now becoming a woman and learning how to be a queen, does alicent think of herself as rhae's best friend, viserys' wife or otto's daughter? So rhae has to keep what really went down in the brothel and in her bedroom to herself cuz she doesn't know who Alicent is loyal to.