If your teenage cousin was only seven the last time you saw her, you might describe her as having undergone a transfiguration, or an enormous physical change.
When a person's appearance changes dramatically, that's one kind of transfiguration. A magician changing a dove into a bouquet of flowers also performs a transfiguration. The word shows up frequently in religious writing as well, describing a more spiritual kind of change. In fact, the origin of transfiguration is mostly religious. While the Latin root, transfigurare, means "change the shape of," transfiguration was first used in English to mean "the change in appearance of Christ."