All Admins and Standard Users will have access to the public items on your My Week when shared with others. So they will be able to see any items that are live on a public or shared timeline(s) that appear in your My Week.

If you have items that are private, they will only see the total number of items in your My Week but will not see any further detail into those item(s).

Keep in mind if you are an admin, it does not give you direct access to all items that a user has assigned to themselves, if the contact and/or work item is private or if the items are not on a public/shared timeline they will appear as private to you.

If you do not wish to share your 'My Week' with others, you can turn off the Colleague's View within your Profile. This will prevent others from having access to your 'My Week'.