Was this why?

"Where... is she? Alicia?" Harold asked, his voice almost sounding pleading.

"It's my body. Why are you looking for someone else?" Amber asked before her angry eyes moved away from Harold to look at the window.

He pushed himself away from the wall, as he could already feel his eyes closing on their own. His body had never experienced this kind of shutdown since he was born. He tried to approach Amber as she looked out the window at the sky.

"It's almost the Blood Moon. I'll be 20 soon." She muttered to herself. 

The tone she used to say it told Harold that whatever she was thinking inside her head was not good. 

Combining the tale he had heard from Sir Richard and what he had found with Alicia, the Blood Moon was a powerful time for witches. And if Anne had asked for Amber to be kept until she was 20, it meant there was something up right there.