After I Was Reborn, I Married My Ex-Husband Again.

Classical fiction, cool writing. She is the daughter of a princess, and the only thing she could do in her previous life was probably to live a long time. She overcame all her love rivals and her dog-emperor husband to become the queen mother, and finally died alone in the palace. Once reborn, return to girlhood. She decided to get rid of that bitch man and live her whole life to her heart's content. But in an accident, he discovered that there seemed to be a hidden secret behind his mother's death and his own infertility. All this seems like a huge conspiracy, and this conspiracy seems to be waiting for her arrival...