Tuula Pere 
The Best Summer Guest [EPUB ebook] 

When Jonty’s parents go away, Jonty is a little uneasy about spending his summer vacation with Grandma Gladys. His grandmother is lots of fun, but Jonty knows he is going to miss his parents.
Spending time with Grandma Gladys turns out to be even more surprising than Jonty imagines. He meets the “Bun Angels, ” watches for a scary pike that lives under the dock, and finds unusual treasures in Grandma’s old dresser. But Grandma’s birthday party turns out to be the best day of all.