Typical Absence Seizures: The presence of 3Hz spike and wave discharges on the EEG, which is a hallmark of typical absence seizures, along with the clinical presentation of staring spells and a family history of seizures, makes this the most likely diagnosis. The extremely frequent generalized spikes further support this diagnosis, as they are often seen in conditions that predispose to absence seizures.

Atypical Absence Seizures: Although less likely than typical absence seizures due to the specific EEG pattern mentioned, atypical absence seizures could be considered, especially if there are variations in the seizure semiology or if the EEG patterns show some atypical features not fully detailed here.
Juvenile Myoclonic Epilepsy (JME): Given the age of the patient and the presence of generalized spikes, JME could be a consideration, especially if myoclonic jerks are present or if the seizures are not purely absence seizures. However, the primary presentation of staring spells and the specific EEG findings make JME less likely at this stage.
Generalized Epilepsy with Febrile Seizures Plus (GEFS+): This condition involves various types of seizures, including febrile seizures, and can present with generalized spike-wave discharges on EEG. The family history of seizures supports this possibility, but the specific details provided lean more towards absence seizures.

Lennox-Gastaut Syndrome: Although rare and typically presenting with multiple seizure types, including atonic seizures, and a slower background on EEG, Lennox-Gastaut Syndrome is a critical diagnosis not to miss due to its significant impact on the quality of life and the need for specific management strategies.
Structural Brain Abnormalities: Conditions such as cortical dysplasias or other structural abnormalities could potentially cause seizures and abnormal EEG findings. Imaging studies (e.g., MRI) are crucial to rule out these conditions, which could require different management approaches.

Landau-Kleffner Syndrome: Characterized by acquired epileptic aphasia, this syndrome can present with seizures and abnormal EEG findings, including spike-wave discharges. However, the primary symptom of language regression is not mentioned, making this a less likely consideration.
Myoclonic-Astatic Epilepsy (Doose Syndrome): This rare epilepsy syndrome presents with myoclonic-atonic seizures and often has a genetic basis. The EEG can show generalized spike-wave or polyspike-wave discharges. The absence of myoclonic or astatic seizures in the description makes this diagnosis less likely.