YA/Young Girl-Growing Up Katie(y) Scholastic Book?

I think I ordered this through school in the 60s. About a young girl who has an older sister and she wants to be grown up like her. I remember a chapter about "the black hand club" where the younger girls started their own exclusive club. Also in one of the first chapters, an old woman visits her mom and her dog chews on the legs of a prized cherrywood table. Also the girl Katie picks and eats cherry tomatoes out of the family garden. I think one of the other characters is named Janet (maybe her sister) and could be that there was a "harvest moon" dance. Your help is greatly appreciated.

Sounds like one of the Katie John books. Maybe this one?

KATIE JOHN
by MARY CALHOUN - 1969 - Snippet view
After supper Katie went down to Sue's house to find out if the Black Hand had reformed Janet. However, she waited on the porch for Sue. The night air was soft with Indian summer, and there was a gorgeous yellow harvest moon. ...

Katie John

That's it! Thank you so much!