People face recognition - On device? Gone wrong with a Macbook.

Face recognition is actually more versatile on the Mac, but it can get confused, as well. Mac's face recognition doesn't give a hoot about your daughter's red hair or blue eyes or your other daughter's brown hair and brown eyes. After all, pictures might be black and white, or people can change their hair and eye color. Face recognition depends on things like the ratio of the distance between the eyes to the distance from the nose to the mouth-- or somethings like that which I have no idea about...

You're right that the face recognition is done with scans on each device-- and even in each Library, if you maintain more than one Photos Library on your Mac. And when the OS changes or lightning strikes or something, it can all go haywire. That's why many of us add keywords to pictures to help out. I make a Smart Album with Person is Ellen. Then I make sure they all have Ellen in them! And then I select all and add the keyword "Ellen" to all of them at once. Now, if there's some craziness that happens, I can make a Smart Album with Keyword is Ellen AND Person is not Ellen and fix the ones that got messed up. Keyword are more robust than faces, and they can export with pictures when you share them outside of Photos.

In your case, things seem pretty messed up. You may have to start over with the kids who are mis-named. You want the Mac to un-learn what they know about the faces, and then re-learn how to recognize each kid. Here's what I would do for 3 kids, Jose, Ellen and Ariana.

First I'd add the right keywords to all picture of the 3 kids. Then I'd make a Smart Album that had the keyword Jose in it, and I'd go through all the pictures and do "this is not Jose." All of them, even the ones that were right. Then I'd go back through them and add the name "KID 1" to all the pictures of Jose. DON'T USE JOSE! The Mac already has a (wrong!) idea of who Jose is! Then I'd do the same with Ellen and Ariana, using KID 2 and KID 3. (Doesn't have to be that, of course-- you could use J, E, and A, or whatever works for you.)

When you do this, you'll get 3 new people albums, and the original 3 should be empty. Then wait a week with the MacBook plugged in all night and with Photos not in the foreground--and hope that the Mac has learned who J, E, and A are for real. And then you can change the names back. Double check the keywords!

Sounds like a lot of work, but the Mac has to un-learn those faces before it can get it right.

Let us know how you do...

I find Photos on my Mac quite useful, but complaining to me doesn't help-- I'm just another user. You can leave feedback, here:

Feedback - Photos - Apple

If you wish to be taken seriously, I would advise a more helpful rather than complaining tone.