Crystal is the youngest daughter of the Inhumans' greatest nutrionalists, Amber and Quelin. Exposure to the Terrigen Mists as a child unlocked her control over the elements. When her brother-in-law, Maxmius, exiled the Royal Family of Attilan, she was forced into her first contact with the outside world.
One of the first humans she encountered was the Human Torch. They began a romantic relationship even against the Inhumans' king, Black Bolt. Eventually, the Royal Family regained power and became friends with the Fantastic Four. Crystal spent a great deal of time with her human friends and even took the Invisible Girl's place during her first pregnancy.
She was forced to leave the team when her allergic reactions to air pollution prevented her (and all other Inhumans) from living on the Earth. Their city of Attilan was moved to the Moon and Crystal went with it. It was during this time that she met the mutant Quicksilver who went with her to the Moon. They fell in love and soon married. Crystal later gave birth to the Moon's first native inhabitant, Luna, who turned out to be a completely normal, human child (The Inhuman and mutant genes cancelled each other out).
Shortly after Crystal and Quicksilver separated, she and Ms. Marvel joined the Fantastic Four to replace Reed and Sue, who took a temporary retirement from super-heroics. (Reed had developed a drug that temporarily enhances an Inhuman's immune system.) She left when Reed and Sue returned and took up membership in the Avengers, where she maintained an active status until she was transported to the Franklinverse. Returning from that reality, Crystal has reunited with her husband and returned to Attilan. With Attilan's unexpected return to Earth, Crystal once more must deal with being an Inhuman in a human world.