Funny, that's not even my highest priority. I wish I could sort by how big or small they are, if they do anything particularly socially or ecologically responsible or something. I want to spend my money at good, human, responsible places.
Check out https://bookshop.org/
Allows you to select a local bookshop to support. The book gets shipped directly from Ingram, with some of the proceeds going to the selected store.
I asked at my local bookshop if this was preferable to ordering the book with them and going to pick it up. They assured me it was, it saves them upfront costs and guarantees the sale.
I still go in when I can to browse new titles, but they don't carry much tech/computer related stuff.
Not parent, but I like, and try to direct money to, local bookstores that do events and provide spaces for small and local authors to reach the community.
If the site also parsed local bookstores (the ones that put their catalogues online) and allowed you to filter for local bookstores, is that something that you would find useful?