Nerakr, yes probably. It depends on the child obviously, but they’re probably right about a 2nd grade level.
And after the first one the next 18 can be read out of order, if I remember right.
Another one of my old favorite series I just got my 8 year old hooked on is the Ramona Quimby books by Beverly Cleary, and her masculine counterpart Henry Huggins. I loved those books when I was younger. I checked out the first one for my 8 yo this morning and she’s hooked.