It is unobservant to lose track of your family members.
Kerry was babysitting her younger brother and brings him to the park.
Kerry wants to talk to her friend on her phone.
Kerry waits until they get home to call her friend on the phone.
Kerry lets her brother run off alone and talks to her friend the whole time they are at the park.
Kerry is able to keep her brother in her sight the whole time they are on the phone.
Kerry can't find her brother and has to call the police to file a missing persons report.