Right - I understand the need to have both logons. However, what I was getting at is whether or not you would be OK with only one of those logons having direct access to the iPhoto library. Here's why I'm asking:
My husband and I have our own physical Macs, so we each have a unique logon that is completely our own. However, for our iTunes library, we use his Mac (and his Mac logon) and for our iPhoto Library, we use my Mac (and my Mac logon).
As long as my Mac is logged on, either one of us can upload and get into the iPhoto library with hassle.
I know there is a way to set up permissions to allow two users to logon to the same iPhoto Library, but it entails the need to remember to physically logoff the user who is last in it (from the Mac) in order for the other user to access it.
So, again, there is a way to do it, but it is a lot more complicated. And if you have no issue being on the Mac doing specific things under the other's Mac logon, then it is easier to keep the Library under only one.
Let me know how you want to proceed, and I'll do my best to help you get there!
Cheers,
GB