Eh... I don't think she's the sort to make a secret account. I think she would dislike idea of excluding people unless she had good cause to. The more likely reason is she's getting in her own head about things, whether it be her popularity, how she looks, or some other reason we're not privy to. She's menhera guys, as many other vtubers are. Check out her normal streams sometimes. You'll get an idea of what sort of person she is.