Written in the stars

This is a fairy tail story but I have made some changes.
Lucy Heartfilia was devastated when Lisanna and Natsu declared their feelings to each other. She had always liked him from afar, but never said so. Even then, she tried her best to be happy for both of them, until she overheard Natsu, Lisanna and Erza talking about her weakness, and the overall incompetence of celestial wizards.
As it is, most people ignored her, except Mira, Gajeel, Wendy and Carla, Gray, Lisanna and Happy. And Master, of course.
She decides to train, and become stronger, and encounters Yukino of Sabertooth, badly injured. She is unable to save her, but Yukino relinquishes her keys.
She now has the zodiac gates, and the forbidden thirteenth one. But will she become strong?
Read to find out!

*No there is nothing about Lucy being a dragon princess, it was too unrealistic, although I personally love that plot.*