Description from Open Library:

TWELVE-YEAR-OLD ASTRID HAS ALWAYS DONE EVERYTHING WITH HER BEST FRIEND NICOLE. SO WHEN ASTRID SIGNS UP FOR ROLLER DERBY CAMP, SHE ASSUMES NICOLE WILL TOO. BUT NICOLE SIGNS UP FOR DANCE CAMP WITH A NEW FRIEND INSTEAD, AND SO BEGINS THE TOUGHEST SUMMER OF ASTRID'S LIFE. --front flap

Description from Google Books:

"A graphic novel adventure about a girl who discovers roller derby right as she and her best friend are growing apart"--

Snippet from Google Books:

"A graphic novel adventure about a girl who discovers roller derby right as she and her best friend are growing apart"--

Description from Harvard Library:

"A graphic novel adventure about a girl who discovers roller derby right as she and her best friend are growing apart"--