Jae Mazer 
Slit Mouse [EPUB ebook] 

Charlotte Beaulieu inserts a soothsaying mouse named Madame Slitoris up her pussy in order to see the past.

After becoming estranged from her wealthy, prominent family, Charlotte grew up on the streets, alone and isolated from the Beaulieu name and wealth, including her brothers Benedict, Algernon, and Cassius. 

But now the Beaulieu brothers have a problem. Cassius has gone missing, and they have no way of finding him. No way except an adult sister who they haven’t seen in years-a sister who carries a soothsaying mouse in her pussy.