This is the 4086th most frequent Swedish word.
pigga
"Pigga" means "to cheer up" or "to invigorate" in English.
In this sentence, 'pigga' is used to describe an energetic and awake state of being.
Hon kände sig pigga och redo att börja dagen.
She felt lively and ready to start the day.
Here, 'pigga' refers to the children being active and lively, possibly after regaining energy from eating.
Barnen var pigga efter frukosten.
The children were energetic after breakfast.
In this case, 'pigga' is part of the phrase 'pigga upp', which means to cheer or enliven something, referring to uplifting the atmosphere.