Sure. One great 'ciel is a girl' fanfiction is 'Ciel's New World'. It explores what would happen if Ciel were a girl in the dark and complex world of the original story. Another one could be 'Girl Ciel's Adventure', which takes Ciel on different quests as a female character.
I've heard of 'Ciel as a Girl: A Different Path'. This fanfiction imagines Ciel's life if she were born a girl. It changes the dynamics of her relationship with Sebastian in an interesting way. For example, some of their interactions become more complex as society's views on gender play a role. There's also 'A Girl Ciel's Destiny' which focuses on how Ciel's gender change would impact her long - term goals and how she has to overcome different obstacles compared to her male counterpart in the original story.