Mark pointed the device at Mom and pushed the “Age Transformation” button.
As he pushed the button, Mark discovered the button slid two ways – up and down, presumably to change the target's age from younger to older. He picked a direction to slide the button, and continued to hold it pointed at Mom.
He presses the button and watches as she de-ages to about the same age as him. It worked! He thought, wondering how she'll act.
"You'd better hurry up," Mark's "mom" urged him as she continued out the room. "Jenny'll be angry with you if you don't." she warned as she disappeared from sight entirely.
Mark just stared in awe at where he last saw his new sister. He received flashes of new memories that overlapped his original dreams. In the place of his mother stood his dad. At his first day of school. At doctor appointments. His new sister, Gwen, was added to family memories. Christmas at Granny's. Soccer games. She turned out to be his twin sister now. He glanced down at the remote. At first he was filled with fear of what he had just done. Then a sensation of power flowed through him.
The sensation was quickly squelched when Jennifer, Mark's oldest sister appeared in the doorway of his bedroom, with her hands on her hips. "If you're not ready for school in ten minutes, I'm leaving you." She barked.