Nina's father was Shou Tucker, the Sewing Life Alchemist.
When her father became desperate in forming another talking chimera he transmuted her and her dog into a chimera that was able to speak the human language. Shortly after, she is killed by Scar to put her out of her misery.
Later on in the first anime, with the philosopher's stone, the disfigured Chimeric Shou Tucker is able to resurrect his fallen daughter into the form of a chimera homunculus, an artificial human being. However, she never speaks and little is known about what happens after that.