Of course, telling someone you got pregnant because of a wish is not the most believable story in the world.
"What kind of nonsense is that?" replied Sarah's mother.
"It's true! I can prove it! I used a wishing stone. I haven't used it for the past few weeks because I was afraid of causing more trouble. But the stone's still here. All I have to do is get it and I can show you."
"Oh? Do tell, young lady."
"I put it right besides my alarm clock. It's a red stone, about an inch wide."
"Well, we'll see." Sarah's mother left while Sarah cleaned herself off. Having even a few drops of your vomit on yourself was no way to become popular, after all!"
And then Sarah's mother returned. In her hand was the wishing stone. "Is this the stone you mean?"
"That's the stone."
"I don't know why you expected me to think there's proof just because you said you had a rock and I found the rock. It's just a rock, it can't grant wishes."
"You tried it, Mom?"
"No, but it can't work. Otherwise I could say something like 'I wish that you and your baby....'"