You may also be looking for another Althea
Althea underworld
Portrayed By Rose Glucina
Appearance Hercules in the Underworld
Affiliations Deianeira
Series Hercules: The Legendary Journeys

Althea was the sister of Deianeira.

When Deianeira suspected her husband Hercules of infidelity, her sister Althea watched her children so Deianeira could find out the truth.

In mythology, Althea was the name of Deianira's mother. Deianira had no sisters, only a brother, Meleager.