Issue with Autofill

I have an account and created one for wife. Created organization and a collection to use for sharing logons/passwords. Here is the problem - when I had autofill selected and was testing wife’s account, it would still autofill MY account info, not hers. My logons are not shared in the collection. The collection only contains logons to HER accounts (that I have set up in mine). So how is Bitwarden able to autofill My account data it in? (Example: we both have Gmail accts. I share her Gmail account data with her but she cannot access mine). My assumption would be another user can only access data 1) they create themselves or 2) is shared with them (this case), and not access data from the “sharer” account.