Missing Photos

[Raven]

Upgraded my wife’s Mac Mini to 10.13.6 last summer.
(Didn’t want to go past High Sierra for a reason).
She noticed later that all her photos were NOT on her Mini.
Only those up to June 2020. None thereafter. But they are all on her other devices using iCloud -  iPhone & iPad2.

Also, I did find a few other odd things that need your advice, please! :-)
In the PICTURES folder, there are several Photo Libraries:
iPhoto LIbrary - 9.1 GB, May 2020
iPhoto Library - 26 GB, June 2020
Photos Library - 28 GB, Nov 2020
Photos Library - 9.5 GB, Dec 2020

Q. Do I have to merge these somehow before I do anything?
Q. How can I get missing photos onto the Mini Photos 3 app?

The Photos app shows a total of 6005 photos, as of June 2020
Yet iCloud.com shows - 7337 photos as of today.
Are those the missing images?
(Aside, I’ve always been confused how to synchronize iCloud on several devices. That’s another topic!)

Thank you all and Merry Christmas season!

[Paddy]

Raven, I don't use Photos for precisely the reasons evident in your issues (bizarre behaviour over which I have no control - how photo libraries are set up, etc. etc.) Sorry - I want to set up my own filing system!! I use Lightroom.

However, to your question about combining the libraries - Apple has a support doc on that:

https://support.apple.com/en-ca/HT209528

As to the missing images - look and see. You can do so via a browser. See "How to access iCloud Photos online" a little more than half-way down this article. https://www.blog.motifphotos.com/using-icloud-for-your-photos-how-to-access-your-photos-on-icloud-2/

[Raven]

Thank you, Paddy. Took me a while to figure this out, but I finally was able to get all iCloud photos onto her Mini. She's happy!
I also noticed there is still an "iPhoto" icon (vs "Photo" icon) on the dock. Should that stay there or can it be removed? It seems that all the photos on iPhoto library go to 2012 and are all included in the Photos library.