Book four is done! i finished Mademoiselle de Maupin and I must say that it was a wonderful book. The ending is great, not because it is a "they lived happily ever after" ending, rather Gautier explains that he wanted nothing more than to state what actually happened, and he did.
She basically ends up sleeping with d'Albert and leaves him the next day, Gautier also alludes to her possibly spending a romantic night with Rosette but there is no proof, and he states that he is unable to find anything in the letters to Gautier's friend nor in Rosette's friend's letters.
It ends with Madeleine leaving both of them, to be independent and let Rosette and d'Albert be happy or be miserable together.