Sunny side up - Jennifer L. Holm

Sunny Lewin has been packed off to Florida to live with her grandfather
for the summer. At first she thought Florida might be fun
-- it is the home of Disney World, after all. But the place where
Gramps lives is no amusement park. It's full of . . . old people.
Really old people.
Luckily, Sunny isn't the only kid around. She meets Buzz, a boy who
is completely obsessed with comic books, and soon they're having
adventures of their own: facing off against golfball-eating alligators,
runaway cats, and mysteriously disappearing neighbors.
But the question remains -- why is Sunny down in Florida in the first
place? The answer lies in a family secret that won't be secret
to Sunny much longer. . .