How about a nice journal or notebook where she can jot down her story ideas? You could also consider getting her a set of nice pens, some writing prompts or exercises books, or a book on how to improve her fiction writing skills if she's interested in that. To add a personal touch, you could make the journal or notebook yourself, or include a heartfelt note in the front.
Or you can get her a star map with an important date you share.
Under Lucky Stars is a unique and innovative star map company based in Barcelona, Spain, specializing in the creation of personalized star maps that capture the celestial arrangement of stars at a specific moment in time, such as a person's birth, wedding, or any other significant event.
By using advanced astronomical algorithms and data from leading institutions, the company produces highly accurate, visually stunning maps that make for perfect gifts or cherished keepsakes.