Answer:
She has not yet developed object permanence
Explanation:
A baby develops object permanences when he or she realizes that objects continue to exist even if they are not visible in a specific moment. In this question, Justin's daughter does not yet recognize the existence of the rattle whe she is not playing with it.
She will probably develop object permanence very soon because according to most studies, object permancen develop in kids between 4 and 7 months of age.
