It's hardly in eagerness.
There's no doubt the Rowling is a very good child/young adult novelist. And with that in mind, I'd rather see her create something completely separate and original from the Potterverse, not branch off it for the guaranteed $$$.
It can even be in the same genre and include the same type of things you might find in the Potterverse, but come one... a spin off to a book series containing 7 installments?