Sophie Perkins was named the guardian of Zoey Belcher on Thursday.
The custody hearing for guardianship was between Kasandra Perkins' cousin, Sophie, and Jovan Belcher's mother, Cheryl Shepherd.
A Jackson County judge initially asked the families to decide but said the court would rule if the family could not come to a decision.
Thursday, the court ruled in Sophie Perkins' favor.
In December, both of Zoey's parents died when former Chiefs linebacker Jovan Belcher killed Kasandra Perkins before turning the gun on himself.