Ok, this should be simple, but I'm totally stuck. My wife and I both have MBPr, mid 2015 portables, both on 10.13.6. We each have an AppleID of our own.

What we want to do is to share images that are currently in my Photos and on my iCloud Photos, but for her to see them from HER account so that she an also then have her own images that she does not share with me. It would be even better if I can have images she doesn't have to have, too.

So, Family Sharing seemed to be the way to go. But we cannot get it to work.

Here is what Apple says to do in Photos Help:
Create a shared album
Select the photos and video clips you want to share.

Click the Share button in the toolbar and choose iCloud Photo Sharing, then click New Shared Album.

Type a name for the shared album, then type the email addresses of the people you want to share the album with.

If you want subscribers to be able to view the shared album from an iOS device, be sure to use the email addresses they use to sign in to iCloud.

Click Create.

Your invitees are sent an email asking them to subscribe to your shared album.
So I did that. But when I added about 700 images to that shared folder, only 190 were actually shared. I tried again, only 177 shared. No email was sent to her for either try.

So I tried another way. In Photos, I selected Shared Albums, clicked on the "+" to add a new album, gave it a name, went to my photos and selected about 700 images and dragged them to the shared album. Nothing, nada, zilch happened.

I tried creating a new shared album, but instead of drag/drop, I clicked on the "Add photos and videos" text, which opened up all my photos, selected a few and clicked "Add." Nothing happened, nothing got added.

In all this, no email ever got sent.

So I tried using the Family Sharing from my iPhone because when I searched the internet for help one place said you could share photos that way. She got the Message and accepted the invitation to the Family, but again, only the 177 images show.

I have a little progress indicator on the top bar of Photos that is showing a pie wedge from noon to about 4 on the clock, not moving. Activity Monitor says Photos is taking no CPU. Basically, nothing is happening. Activity Monitor shows no network activity, no disk activity, no major CPU activity. Nothing is happening at all. Activity Monitor does NOT show Photos as not responding, just that it's taking 0% of the CPU, and Photos is responding to my mouse, but the progress clock isn't moving at all.

We have about 4500 images we need to share. Is there a limit of 177 images per shared album? Do I need to create 40 albums, 177 at a time? Is there a secret that Apple isn't telling about sharing? Am I missing something?