The owl looks at her and hoots in confusion, but flies down to her arm and offers her one of its feet, which already had a letter attached.

Sarah takes her reply out and asks, "Can you take this to Professor McGonagall?"

Hoot.

It was too much to hope that her new talent for talking to animals would extend to mail delivery owls. Sarah exchanges the letter tied to the owl's leg for her reply. "Thank you."

It hoots again and takes off.

She hides the letter under her dress and goes back to gardening for real. It's probably the same as the last one but it won't hurt to check.

Petunia sticks her head out the window. "What are you doing out there, girl?"

"Gardening, it's starting to get hot in the afternoons so I wanted to get an early start."

"Well, come inside! You can do that after breakfast."

Sarah already ate but she nods. "Yes Aunt Petunia," then dutifully walks inside dusting the dirt off of her clothes.

And to Uncle Vernon's unvoiced satisfaction there are no letters today.

Well, she's very glad that the Dursleys have only seen one letter.

Dudley's in a sour mood, banging walls and objects with his stick.

Sarah tries to stay well out of his reach and eats more breakfast.

Vernon goes to work and Dudley waits for his friends to arrive.

Sarah goes off to her room to inspect the second letter.

It's identical to the first.

Then she'll hide it with the first and continue working on tidying up her new room.

No more letters arrive over the next couple of days.

Hopefully that's because they got her reply. When she has a convenient moment she'll ask Petunia about what do with all the broken toys.

"I'll get them," she says, and does, taking them downstairs, and Dudley throws a tantrum about that.

"Thank you Aunt Petunia." Her room is neat now, that's what's important. What's left with the broken things cleared away?

A bed. A wardrobe. A small desk. A chair. A beside table. A lamp.

Hm, did she notice any loose floorboards while tidying up? Does the bed or any of the other furniture have spaces underneath it that are hard to see into? She needs somewhere to hide the letters and it'll be suspicious if she doesn't hang up her clothes.

No loose floorboard, yes space under the bed.