You can either use separate accounts and share sites with eachother, or a single account and use the 'identities' feature. Normally it's used to separate groups of passwords, such as ones for work and home, but you can use it as a quasi multi user profile.
I strongly suggest using password sharing instead of single account identities, not only from a privacy perspective, but a safety one. You can still manage your shared passwords, and most normal users will not know how to capture a shared password. It is great for sharing login info to a resource without resorting to giving it out in a post/text/email, and keeping that info current. You can even update the password, lets say you change the password every week for security purposes, everyone who has been shared gets the updated password automatically. That, and you are not exposing your entire database of passwords to anyone who could make mistakes in handling your account.