What is the test for changing a child's name to include his mother's maiden name?

Vanderlinde v. Bohn involved an application by a child's mother to have his surname changed to include her maiden name hyphenated with the father's surname. The mother had primary residency of the boy, and the father exercised regular access and “played a meaningful role in his life.” The boy was already known by the hyphenated name, as his mother had informally changed it to "Timmerman‑Bohn".