Looking for the title of a sci-fi book with a character who is a girl that was manipulated genetically or technologically to be able to communicate with an alien species from Jupiter. Her intestines were replaced by the communications device, which was later removed by a doctor who thought it was a kind of parasite. Somewhere along the book, she is addicted to a drug and lives in the ventilation shaft of a spaceship, or maybe just a ship. The contact with the aliens ends up being made by a cyborg man in a dirigible.
During her infancy/teen years the girl used to like a lake designed as a mandelbrot fractal.