The Truth About Stacey (The Baby-Sitters Club #3) by Ann M. Martin

Brand new but there are some minor imperfections as shown.

A fresh new look for the beloved series -- set to relaunch just after a brand-new prequel hits stores! The truth about Stacey is that she has diabetes, a fact she keeps secret from everyone except her new friends in the Baby-sitters Club. But Stacey's condition causes a lot of problems, and she has to miss a lot of BSC meetings. Can she find a solution before her new friends get sick of her disease?