This can be a great thing and you'll work it out.
Having a basic checklist is something you can build and then just keep it posted somewhere (like on the inside of a cabinet) where you can check off items that are needed.
Giving her a sense of favorites, price sensitivity etc... is good. Shopping with her a couple of times is also a great idea.
And then, be prepared to lose a little bit of control, occasionally pay more for an item than you might have chosen to, occasionally not have your favorite brands etc... But also, you'll occasionally get exposed to things you wouldn't otherwise have thought of, and someone else is doing your shopping for you! Is the value of your time worth as much as the small (potential, not definite) cost of not being fully in control? Probably!
You'll figure it out together.