Can a former stepparent be required to continue financially supporting a stepchild after separation?

Yes. A former stepparent who stood in the place of a parent to a child during the relationship can be ordered to continue paying child support after separating from the child's parent, even though they have no biological or adoptive connection to the child. This is a well-established feature of Ontario and federal family law: support obligations can attach to someone who voluntarily took on a parental role, not just to a legal parent, because the law focuses on the reality of the relationship the child relied on.

Whether a former stepparent is actually found to have stood in the place of a parent depends on the specific facts - how long they lived with the child, whether they contributed financially and practically to the child's upbringing, and how the relationship was generally understood by the family, including the child. A stepparent with only a brief or peripheral involvement is less likely to be found responsible than one who effectively co-parented for years. The exact amount of any support obligation typically still involves the guideline child support tables, though a former stepparent's obligation can also be adjusted based on their specific role compared to a biological parent's. Get legal advice specific to your situation if this issue comes up.