I have an ecommerce site set up, and my client is currently tracking her inventory manually. This means, if she sells something in store that’s also on the website, she has to go into the Editor and adjust the inventory quantity.
Is there any way to connect her in-store system (Square), to update inventory on the site as well?
There is no native way to do this. You should explore what is possible with Zapier, Integromat, or similar services. Development via the respective API’s is also a possibly.