| 1797 | Mary Wollstonecraft dies ten days after giving birth to daughter. |
| July 1814 | Mary Godwin (Shelley) runs away with Percy Shelley. She is 16 and pregnant. Godwin refuses to communicate with her. |
| November | Harriet Shelley (PS's wife) gives birth "to a son and possible heir." |
| February 1815 | Birth of a daughter: illegitimate, premature, and sickly. |
| March | Baby dies. |
| April | Pregnant again. |
| January 1816 | Birth of a son. |
| March | Claire Clairmont (younger step-sister) pregnant by Byron. |
| June | Begins writing Frankenstein. |
| October | Fanny Imlay (older half-sister), commits suicide after discovering she is not Godwin's daughter but Mary Wollstonecraft's daughter by an American lover. Godwin refused to claim body, which is thrown into a pauper's grave. |
| December (early) | Pregnant again. Completes chapter 4. |
| December (middle) | Harriet Shelley drowns herself in the Serpentine; she is pregnant by someone other than Shelley. |
| December (late) | Marries P. Shelley. |
| January 1817 | Claire Clairmont gives birth to daughter. |
| May | Finishes Frankenstein. |