Q: Storage

iCloud Photo Library is accessed under Settings > iCloud > Photos > turn on in there.

OK, a couple of questions:

1.     Under Settings>Photos & Camera, do you have iCloud Photo Library turned on?

2.     When you indicate that you have another iPhone in the family that does save to iCloud, are you talking about iCloud Photo Library, and do you have the same iCloud account signed in for that device?

Here are a couple of articles that may help you regarding the usage of iCloud Photo Library:

iCloud Photo Library FAQ - Apple Support

iCloud Photo Library Help - Apple Support

Best of luck,

GB

OK, so not sure what the question is? What are you looking for and expecting to see?

Cheers,

GB

Are you certain that you have enough storage on that iCloud account for all the photos to upload to the iCloud Photo Library? If you are using a Mac, you can go to >System Preferences>iCloud>Manage (bottom right-hand corner of window)>Change Storage Plan. A screen will come up that indicates what level you need to store your entire Photo Library:

As you can see from this screenshot, if I was wanting to use iCloud Photo Library, I would need to upgrade my iCloud Storage to the 200GB Plan.

If you don't have enough storage to hold the entire library, it won't attempt to upload anything.

Cheers,

GB

Well, in looking at Apple Support articles, I did find one that showed a picture of the iCloud sign in screen for Windows. On it, I see a button for "Storage". Try clicking that to see if you can see the same path that I indicated above. Here is the article that has the pic:

Download iCloud for Windows - Apple Support

Cheers,

GB