"Who is she, really? Why is she here? Not for gold, I'd judge. What is this prince to her? Was she ever a true septa?" — "A Dance with Dragons", George R.R. Martin

In "A Dance with Dragons", the fifth book in "A Song of Ice and Fire" by George R.R. Martin, Tyrion Lannister encounters Septa Lemore, a supposed septa who behaves strangely and has had a child before. Since then, fans have speculated as to her true identity. (I've tried to include all of the major theories, but anyone can add another option.)

This Reddit post discusses some of the theories about Lemore's identity: https://old.reddit.com/r/asoiaf/comments/66ao8w/spoilers_extended_theory_discussion_the_septas/

I will not resolve the market on the basis of rumours, leaks, or ambiguous comments by Martin. If it seems likely that the remaining books will never come out (even posthumously), then an announcement as to what her true identity would have been (e.g. based on Martin's notes) is sufficient to resolve this. If even that does not happen, this market will resolve N/A.