I think I see what you’re getting at here.
It sounds like your co-worker has two Asana accounts, and you’ve invited both of them into your Organization.
I recommend that she merge these accounts.
It may be important to note that Asana accounts (emails) can be associated with any number of Asana Workspaces or Organizations. Each of these Workspaces and Organizations are completely separate from one another, but you can use one account to access them all.
Your co-worker can merge accounts by following these instructions:
Once she’s done so, she’ll be able to access all her spaces when logged in with either address, and you’ll also only see her once in your Organization.
As an example, I have my work and personal email address in my one account, and I’m a member of my work Organization, as well as some personal Workspaces.