Partie 2: The white or the blue cup ?

He was so thoughtful, Désirée thought. He was going to sacrifice their happiness for her sister... That sister who had always strutted with her innumerable conquests, whereas she, Désirée, was alone. And suddenly, all the hatred she had tried to repress for many years burst out. Aimée had got all she had always wanted. But now, Désirée thought, it was her turn.
She dreamt up a Machiavellian plan to do away with her sister: a violent poison... Her death would be quick... After all she didn't wish to make her suffer long... And it would be the perfect murder: who could suspect her, the little beloved sister who was so discreet, even so frigid? Nobody would know. After a few months, she could get married to Andrew like in fairy tales!
She asked one of her servants for two cups of tea: one must be white, the other must be blue since that was Aimée's favorite colour. Désirée poured some poison into the blue cup and after a few minutes, she called for another servant. "Marta, could you please bring these beverages up to Princess Aimée's room in a little while? I will have tea with her, she hasn't seemed to feel good this morning." Then Désirée rushed to her sister's bedroom and without knocking at the door, entered into the room. But what she saw there made her feel stunnned.
Andrew, pressing himself against Aimée like a leech, was kissing her with eagerness. When they finally noticed Désirée's presence, Aimée had a slight cough whereas Andrew was no longer quite so high and mighty. Then Marta knocked at the door, came in, put the cups of tea on a little table and waited for the princesses' instructions.
" I had thought we could have a cup of tea together. I didn't know you were not alone...", Désirée paused. " No, you're welcome!", Aimée smiled. She was so self-important, so glad to be seen with her fiancé, Désirée thought. Both made her feel sick. " Marta, Aimée said, could you please bring another cup of tea ? You will have a cup of tea too honey, won't you?"
" But... Certainly", Andrew had a weak laugh. " With pleasure." Désirée slowly looked at the two cups: life was contained in one, death was in the other one." Please, don't wait for me. Your tea is getting cold!" She held a cup out to Andrew.

Now the point of this story is this: did she give him the blue cup or the white one? The answer doesn't depend upon myself. Think of it, reader, regardings your aknowlege about human feelings. Would she kill her sister (as planned) to change her life? She wouldn't live in the shadow of Aimée anymore. Or would it not be better for this desperate woman in love to poison her unfaithful lover, who betrayed her using the rivalry which existed between the two sisters? But we can also suppose that she could commit suicide: she would drink the mortal cup of tea and leave the third one to her sister. Like Dido or Cleopatra, the two tormented and sublime heroines that had upset her, she would die and play the main part oh her own tragedy.
So I leave the question of her decision to you. Which cup of tea did she give Andrew? The blue, or the white one?