IF YOUR FATHER HAS BEEN PRESIDENT OF THE United States for a whole week, there are a few things you might want to know:

You shouldn’t run through the first floor of the White House in pajamas. You might run into a press conference full of adults who will stare at you.

You should ask your parents before you decide that it’s your mission to welcome kids to the White House and invite a whole tour group to play in your bedroom.

You don’t automatically get a pony.

You do get a Secret Service agent who will let you talk to his friends over his walkie-talkie.

You don’t want to eat too many of the White House chef’s Porter Butter cookies. Especially the night before your first day of school.

Liberty Porter had only learned this last one this morning. She had sneaked an extra cookie after dinner last night. Okay, three. And now she was lying in bed with a sickish stomach. She was slightly nauseous and also slightly nervous. Because today was Liberty Porter’s first day at her new school!

She had woken up way before her alarm clock was set to ring. It was so early that it was dark outside, but she couldn’t go back to sleep. She thought about getting up and going out into the house. But she didn’t want to wake her parents up. The president of the United States had to get a good night’s sleep.

That’s what her mom had told her the first morning, after Liberty woke up before her parents and went to the White House movie theater. She hadn’t meant to turn the volume up that loud.

And what her mom had said the second morning, after Liberty had woken up before her parents and decided to play upstairs. She had planned to play the drums in the music roo