stepdame

By using the lines, "These O protect from stepdame's injury", Bradstreet is calling for her children to be protected from the abuse of a future step mother.

Such as driv'n out From Athens, by his cruel stepdame's wiles, Hippolytus departed, such must thou Depart from Florence.

This Order, therefore, may prove a nursing-mother to sects, but I shall easily show how it will be a stepdame to Truth: and first by disenabling us to the maintenance of what is known already.

And here's a grating, through which the sun squints on you like a stepdame, and the breeze blows, as if it meant to tantalize you with a sigh from that sweet mouth, whose kiss you must never enjoy.