What it means to adopt your stepchild
A stepparent adoption creates a legal parent-child relationship between the adopting parent and the stepchild. It gives both you and your stepchild many legal rights and responsibilities, some of which continue into the child’s adulthood. Here are some of the more important aspects. The law treats you as if your stepchild were your natural child. You become legally responsible for the care, education and support of the child until he or she is an adult (or even after, in some situations), and you have the right to exercise authority over the child. He or she has a child’s right to inherit from you, if you die without a will. You have a corresponding right to inherit as a parent. Your adopted child loses almost all child-parent rights with respect to the absent parent. (For example, those rights conferred by your province’s “inteprovince” succession laws.)
The child may, however, still inherit from the absent parent, if that parent dies without a will and the child and the absent parent ever lived together as parent and child. Of course, adoption doesn’t affect wills; the absent parent could always leave your adopted child money or property by naming him or her in a will. Also, if the absent parent dies after the adoption, your adopted child may still be eligible to receive Social Security death benefits if the deceased absent parent had a Social Security account. Relatives of the deceased absent parent may be granted visitation rights with your adopted child if they apply to the court.
The absent parent loses all parental rights and obligations when his or her child is adopted. Thus he or she has no right to visit the child, and no obligation to provide support. The child is also relieved of any responsibilities he or she might have to the absent parent.
The changes in these rights are permanent. An adoption decree cannot be set aside unless there was a serious legal defect or fraud in the adoption action, or, in some provinces, unless the adopted child is discovered to be developmentally disabled or mentally ill within five years after the adoption.