Here's the legal definition:
A stepchild is a child born to or legally adopted by your spouse before your marriage whom you have not legally adopted.
https://www.law.cornell.edu/wex/stepchild
In order for a dependent to be claimed on a federal tax return, they must meet the IRS criteria - regardless of rulings by a local court.
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
