@casanice Good question. I am not aware of a way to do so with your screenshots, but there are some methods people do that use external images (which your screenshot .png images would also be) and they have their sim paint or photograph the image in a special manner from a different lot so that they will not be considered CC. I will add a link to a thread about this after my note.
Having said that you can have your household sims take in-game photos with one of the cameras (buy mode in creative items). Those pictures will enter your sims' inventory and can be framed and hung on the wall. You can even add a sim who is a skilled photographer with a very nice camera into your household then you can control them and your family and pose the family and have the photographer take their family pics... then just grab the pics from their inventory and move them out.
https://forums.thesims.com/en_us/discussion/915498/tutorial-creating-nocc-paintings-for-the-gallery
