April Fool's on the 5-year-old

Over the years, we've pulled off some pretty good April Fool's jokes as a family.
We kind of have this tradition of being cruel to one another for fun.
One year we convinced my British son-in-law he was being deported. Another year we told Marc he was in big trouble with his boss. We convinced my son his wedding invitations had been spoiled and had to be redone. We've made sure we've come up with jokes that live on.

This year, it was harder to think of a good joke because a number of topics were off-limits such as joblessness (who thinks that is funny?) and my dad's future (looks pretty bleak from here) and babies (since we lost our John it doesn't seem appropriate to make twins jokes or labor jokes, etc.)
But it's important to keep up traditions so when Adell called to tell me "an April Fool joke," I bought into it with energy.
"Grandma," she said all breathless and excitedly, "I took your new owl into the play yard and it got all ruined."
She waited while I pretended to panic and fret. (This was the new Hedgwig owl I brought at The Wizarding World of Harry Potter for $30 and lent to her with strict instructions on how to care for the stuffed creature.)
"I April-Fooled you!" she said with delight. "It's not really ruined, grandma."
I sighed with relief and told her to watch out because I might call back with an April Fool's joke of my own.
I then went about my morning chores trying to think of a joke I could play that wouldn't break a little girl's heart or unduly upset her.
She is, after, just 5 years old and she trusts me implicitly.
I didn't want to promise a trip to Disneyland or a visit from a Princess or anything that couldn't be true.
I finally thought I had it.
I speed-dialed her mom who called her to the phone.
"Adell," I said. "Come quick. There's a Barbie on a pink unicorn in our backyard!"
She paused and sucked in her breath, not really digesting how far out the idea of such a thing really was.
"Can I come see it?" she asked.
Uh oh.