I have been an Enpass user for several years, Thanks.  I have purchased Enpass for my wife to use, I have sensitive business requirements that make it impossible to share an account. How can I display two Enpass accounts on the same computer? They use separate emails.

Enpass only supports one primary vault. There's no selection involved, the primary vault then opens all the additional vaults that are configured. 

In your case you need to make sure that you and your wife has separate logins to the computer itself. That way you can also have separate primary vaults. 

Do note that the Account for App itself is only used for subscription / licensing purposes and is not tied to your vaults at all, so sharing that with your wife doesn't imply sharing vaults or items.