Spending the summer at her grandmother's seaside house, preteen
Nelly discovers a magic chemistry set. With the help of a male
friend she's made, they concoct a youth potion; they test it on
Grandma's dog, and sure enough, the next day he's just a puppy. So
they use it on Nelly's grandmother, and the next day she's a young
adult woman. But then Grandma keeps getting younger and younger.
She becomes a teenager, then a girl Nelly's own age, then a
pre-schooler, and finally a baby the pre-teens have to diaper. The
dog has disappeared, and it looks as if the same fate awaits
Grandma if Nelly and her friend don't find a solution, and quickly.
Link on the author's website
originally posted by Cobe on 2013-09-26, 3 edits, entryid=9056