CrossOver Pro has a feature for this type of thing, but CrossOver Games does not.
You may be able to use a symbolic link or the like, but you have to get the permissions correct so that both accounts can access the files in the bottle folder. You can do that using the Finder's Get Info window. In the Sharing and Permissions section, you can add your wife's account and give her Read & Write permissions. Then, you'd select "Apply to enclosed items" from the gear button menu.
You should never both be running programs from the bottle at the same time. That could happen with Fast User Switching, for example.
When you share a bottle this way, there will not be a distinction between your user accounts within the bottle. That is, your settings, saved data, preferences, etc. will affect her use of it, and vice-versa.
When new files are created in the bottle, they may end up being inaccessible to the other account. So, you may have to repeat the "Apply to enclosed items" step. Depending on how the game works, this may happen every time you use it.
As you can see, there's a lot of potential for problems and this is a totally unsupported and untested configuration.
Another possible solution, also unsupported and untested, would be to move the bottle to an extra drive or partition on which you disable permissions ("Ignore ownership on this volume" in the Get Info window). Similarly, you could move it to a disk image in a shared location (e.g. /Users/Shared), because ownership is typically ignored on mounted disk images, too. (You would have to give both accounts read and write permissions on the disk image, itself.) Then, you'd create a symlink to the bottle folder from within each account's Bottles folder. Of course, for the disk image, you'd have to be sure it was mounted before launching CrossOver and then quit CrossOver and unmount it if you switch users (it will be unmounted automatically on logout).
