I want to share iphoto libraries between users but not make a copy of my entire library

I want to share an iphoto library between 2 users. I have my entire 75gb library saved onto the hardrive on one user account. I have now created a user account for my wife so that she can use photo-sharing with her phone, and I want her to have access to the same photo library. How can I give her user account access to the photo library without making a copy of this 75 gig library?