I'd pick one of your other children and have Ana help that child set up a system. I'd say even your fourth grader could be in charge of the family library books, given the right system.
Of course, the "right" system for your family might look very different from some other family's system. But I think there are enough common denominators to draw from, like visiting on the same day, keeping books in one location, consistently checking the account, etc.
I'd never give up the library. I say when I am old I want to live where I can walk to the library and Wegman's. :lol: