Switched to "family" ID system, now can't sync photos :(

According to this article, I think you described it right:

iPhoto: Overview of iCloud Photo Sharing

All I can suggest is to check if Photo Sharing is setup on your Mac according to this:

Photos for OS X: Turn iCloud Photo Sharing on or off

and

Photos for OS X: System Photo Library overview

Some other helpful resources might be:

iCloud Photo Sharing FAQ - Apple Support

iCloud: Set up iCloud Photo Sharing

It's working as expected, you each have different accounts, your photos shouldn't sync with each other and the Photos app on your computer can only sync with one account.

You should set up a user account on the computer for the wife to use for herself, that way she can sync her own photos with her own photo app on the computer.

Any photos you want to share with each other you should put into the 'Family' shared album, which got created when you set up family sharing.

I really don't advocate anyone sharing an ID, it leads to all sorts of issues, I suspect we all take photos our partners aren't interested in and perhaps would delete photos our partners wouldn't. I for one wouldn't want any 'Take That' photos in my photo album. However that being said, it sounds to me as though your problems were with sharing the same ID for messages and FaceTime, there isn't actually any reason you couldn't share your ID for iCloud and use separate ID's for messages and FaceTime.

On the phone:

you sign in for iCloud at settings > iCloud, you'd simply use the same ID there. However you sign in for messages at settings > messages > send and receive, you'd each enter your own ID there, same thing with FaceTime (settings > FaceTime)

On the phone

Settings - Messages - iMessage - Send and Receive - click on the Apple ID and choose sign out - then sign in with a different one

It may be "working as expected" according to Apple, but as a family this is unnecessarily cumbersome. Everything was fine w/ ONE Apple ID, until things started getting wonky last fall.

How about "working as designed"

As pointed out, the family's photo needs should be covered via the shared Family album that everyone can contribute to.

Winston's idea will work too, but keep in mind you will now all share contacts, calendars, notes, Safari bookmarks and browsing history and all the other iCloud services that are synced between devices by using the same Apple ID for signing in to iCloud.

You may have to pick your battle.

but keep in mind you will now all share contacts, calendars, notes, Safari bookmarks and browsing history

That's not entirely necessarily so, It's possible to log into 2 ID's (a primary and secondary), there are some things that you must share if you each use the same ID as a primary such as Photos and documents, but you can turn contacts, calendars, notes etc off for the primary and use the secondary ID for these so that they aren't shared.

Winston Churchill wrote:

but keep in mind you will now all share contacts, calendars, notes, Safari bookmarks and browsing history

That's not entirely necessarily so, It's possible to log into 2 ID's (a primary and secondary), there are some things that you must share if you each use the same ID as a primary such as Photos and documents, but you can turn contacts, calendars, notes etc off for the primary and use the secondary ID for these so that they aren't shared.

Which why I also said >>>and all the other iCloud services that are synced between devices by using the same Apple ID for signing in to iCloud.<<<

Unless I just don't grasp how one signs in to iCloud on one device using 2 different Apple IDs.