Though you'd never know it from a lot of quotation sites (including, I've discovered, my own), there is in fact a difference between Mary Wollstonecraft and her daughter Mary Shelley -- which difference is sometimes muddled by the latter sometimes being known as Mary Wollstonecraft Shelley, and both of them sometimes being referred to as Mary Godwin (after MW's husband, and MS's father, William Godwin).

Mary Wollstonecraft was a philosopher and commenter on human rights. Mary Shelley was the author of (among other things) Frankenstein. Their quotations are quite different, but often appear misapplied one author to another.

So when recording in a quotation from one or the other of these ladies, do a little bit of research to confirm that your source has the right author. There's enough bad quotation info out there -- no point in adding to it if you can help it.