The only way to do it is to start from scratch.  A 2nd store can be created, but you need to do so with a different email address than your current store.  There is no way to link the stores or the profits.
 
Hope that helps  

Lisa,
 
You have to remember that as you create designs everything is thrown into the soup so to speak.  A customer shops for cards based on a breakdown of category and sometimes by keyword searches.  Having seperate stores is an advantage mostly if you are doing a lot of self promoting and directing your own clientele to a specific genre, say that you are a wedding planner and want a store that caters strictly to weddings and you give any of your contacts the link to your store only.  Even then, they can easily click on one of the designs in the sidebar and venture off to other artist's stores.
 
My store is a mix of everything, but some artists choose a specific area of interest, a prime example is Sherry's store, Dog Tags and Combat Boots which I think is really clever and she has an excellent niche.
Just using her as an example.  Still noone will find her store directly unless she gives them a link or they happen upon one of her cards searching for something military related, like that design and click on her artist name at that card's page.
 
You can also create individual galleries within your store, for example in your case, A gallery called My Fathers Pictures or whatever you want to call it.
 
Best, Randy