noun, plural step·child·ren.
Examples from the Web for stepchild
Being a stepchild, she noted, set her as an outsider within a family, and gave her a yearning to conform.
You see I'm—I mean I was a stepchild 'long as father was here.Mary-'Gusta|Joseph C. Lincoln
So, for the first time in their lives, met the child and the stepchild of Louise Duval.The Parisians, Complete|Edward Bulwer-Lytton
And she had half-a-dozen servants; the tenor's stepchild was wheeled to the Heath now in fine apparel by a competent nurse.The Quaint Companions|Leonard Merrick