Client password on personal/ pro accounts

As far as I can understand the Workflow for creating web sites for clients is this:
(1) I purchase a personal/ pro/ team account;
(2) I make a web site for my client;
(3) when I am ready I ask my client to open a Webflow account;
(4) I transfer the web site from my account to his.

Unless I am wrong for how it works so far, my question is, is there a way to keep the client’s web site on my account and have two passwords - my own and one for the client?

This is important for me because some clients do not want to remember any passwords and would never log in to edit the site, but still want to make sure they have ownership over their site, while, at the same time, they would call me often to make changes and I need to have access to their web site at any time.

Pretty much. The much better option though is to export the code and use a 3rd party host. You keep the site of the client unpublished and when the client wants to change, you edit the site in Webflow then export the code again and sync with the 3rd party host.