Jon's mom almost did a triple take. She watched Jon (or who she thought was Jon) walk down the hall, presumably to his room. She could have sworn that her son was wearing a skirt, but that couldn't be right. Could it?
Since Jon's mom heard her own wishes, she didn't know that Jon was no longer a boy (at least in the normal sense of the term).
She walked down the hall and peered into Jon's bedroom. It was totally different, now looking like a girl's room, instead of a boy's room! She walked inside and saw what looked like a girl sitting on the bed, taking her shoes off.
The girl looked up and said "Mom? What's wrong?"