She was kidnapped by Hades and given a pomegranite which bound her to Hades forever. She was able to visit her mother, Demeter, only once a year for six months and then anther 6 months with hades
Kore the Maiden of Springtime became Persephone the Queen of the Underworld, wife of Hades at her kidnapping at the hands of Hades.
In Greek mythology, Demeter is the goddess of harvest. Her daughter is Persephone. Hades is the god of the underworld and he kidnapped Persephone. To make a long story short, there was an agreement made between Hades and Demeter to share Persephone. When Persephone is with Hades, Demeter is so sad that nothing will grow and that is why winter happens.
She would have to spend a part of the year in the Underworld.
Persephone would have to spend a part of the year in the Underworld with Hades.
Persephone would have to stay in the Underworld for a part of the year.
There is no other mythological explanation.
Persephone did eat something in the Underworld. She was given pomegranate seeds to eat, which she did, thus binding her to the Underworld for half of the year.
If Persephone ate anything in the Underworld in Skellig, she would be bound to stay there forever. Eating anything in the Underworld breaks the rules and traps the person in the realm.
The kidnapping of her daughter, Persephone; by Hades, and permitted by Zeus.
She could not then leave the Underworld, and would have to return for a portion of the year.
Persephone enemy was Methane because she slept with Persephone's husband, Hades.
Persephone would have to spend a portion of the time in the Underworld; as the pomegranate was grown there.
Persephone would have to spend a portion of the years time in the Underworld (Winter).