"What about what's-her-name, your friend—Yvonne?"

"On vacation in Majorca," she says.

Speaking up would not be useful to her. Though she does roll her eyes at the long list of places they think of pushing her off to.

"I suppose we could take her to the zoo," she says slowly, "...and leave her in the car..."

That sounds unpleasant. Hopefully they'd park in the shade if they decided to do that. Otherwise, she might have to do something rash.

"That car's new, she's not sitting in it alone..."

Dudley begins to cry. Or rather, he scrunches up his face and starts wailing—he hasn't really had a real cry in years.

"Dinky Duddydums, don't cry, Mummy won't let her spoil your special day!" she says, flinging her arms around him. 

"I... don't... want... her... t-t-to come!" he yells between huge, pretend sobs. "She always sp-spoils everything!" He shoots Sarah a nasty grin through the gap in his mothers arms. 

She knows with that odd sense she sometimes gets that he's not actually upset. She closes her eyes and rolls them where nobody can notice.

The doorbell rings. "Oh, good Lord, they're here!" she says frantically and goes to answer the door.

Dudley immediately stops pretending to cry to welcome his best friend, Piers Polkiss, the one who usually holds Dudley's victims' arms while he punches them.

Vernon goes to greet them—

—and Petunia excuses herself and walks back to the kitchen. "Girl, come here," she tells Sarah, and goes to an out-of-the-way corner.

Sarah follows.

When she's sure no one else will hear, she turns a very stern face to Sarah. "I will be very, extremely put out if—any funny business happens. Do you understand, girl?"

"I understand Aunt Petunia." Sometimes strange things happen around Sarah. Usually it only happens when she's feeling strong emotions. She gets the sense that the Dursleys know more about it than they're telling her, but none of her attempts to control the phenomenon have worked.

Aunt Petunia squints at her and looks about to say something else, but thinks better of it, deciding to just return to the living room to talk to Piers' parents.

Soon enough they're gone and the Dursleys plus Sarah and Piers are to go to the car.

Sarah gets in on one side of the car hoping she won't be forced to take the middle seat between the two boys.

Eventually they reach the zoo where Dudley and his friend were to spend the former's birthday. The Dursleys stop at an ice cream stand in front of the entrance and get large chocolate ice creams to Dudley and Piers, but before they can usher Sarah away the lady inquires as to what she wants.

Sarah asks for an ice pop, it's small enough not to be an imposition, and unlikely to be pushed from her hands by one of the boys.

Uncle Vernon dutifully pays for it and doesn't even complain.

Into the zoo they go.

Sarah stays reasonably close always keeping half an eye on the Dursleys and Piers but keeps her distance a little and tries to enjoy herself.

At lunchtime they eat at the restaurant, and Dudley throws a tantrum because his knickerbocker glory doesn't have enough ice cream on top, so Vernon buys him another one and Sarah's allowed to finish the first.

It's not her favorite but it's still a sweet so she'll finish it gladly.