In Kings Landing you do not see women as assassins. Women were to aid after children and the elderly. To care for their husbands and such. Not once did she find that it was possible for a women to kill a man. Perhaps that may be childish of her, but women were weaker than men. At least that was what Sansa had thought.
She was the talk of the town. Her name was spread all throughout the kingdoms, even stories and songs were made of her.
And there she was: Lady Kasta.