Signora was once a mortal woman. She had a tragic past that led her to make a pact with the Fatui. Her experiences, like losing her loved ones perhaps, hardened her heart and made her seek power within the Fatui ranks.
As of now, the Genshin manga is not finished. The story is still evolving and there's more to come for fans to enjoy. The creators are taking their time to develop a rich and engaging narrative.
There's no definite answer yet. It might continue if there's enough demand and the creative team has more story to tell. But it could also stop if they feel they've completed the story arc.
There is a Genshin Impact manga available. It brings the game's world to life on the page with beautiful art and engaging storylines. It's a great companion to the game.