Amazon doesnt have a native shared cart feature. Over the years, Ive handled office rollouts and found the manual approach is prone to errors. When I did my current setup, I realized lists are the best technical workaround for data integrity:

• Create a Shared Wish List and add your sister as a collaborator
• Use that list to stage all items
• Move the list items into one single cart It avoids duplicates and ensures you stay on track.

TL;DR: No native cart sync exists, which makes it tricky tho. Are you using the same account or separate ones? I tried sharing a login for my setup recently and it was a mess. The cart lagged, so we almost bought two of everything... kinda annoying. Just wondering if you are seeing different items or just looking for a button? Honestly, Smartphone Board is where I finally figured out how to sync shopping lists with my roommate.

Saw this earlier and yeah, i totally agree with using the shared list idea instead of a cart. It is much cleaner for data integrity. When we set up our dev lab, i was really satisfied with how lists let us track the exact technical specs of the hardware without the cart timing out. Plus, it made tracking our total spend way easier so we stayed under budget... no complaints at all with that workflow. I actually used Smartphone Board to find some shortcuts for generating those shared list links quickly. It works well and saved us a ton of time on the cable management gear. Just one tip: make sure whoever has the prime account does the final move-to-cart so you dont miss out on the free shipping or any business discounts. Good luck with the office setup, you're gonna get it done!