Is it possible to "share" google photo shared albums without making it public for everyone?
Unfortunately, this does not seem possible with the current version of Google Photos.

I recommend you suggest a feature by:


Opening the google Photos app or going to photos.google.com
At the top left, touch or click the menu icon > Help &amp; Feedback (or Send Feedback)
Touch or click Feedback.


Source: How to get feature requests/feedback to the Google Photos team