Multiple sites-one carousel

I have a site that is only used for a limited, small audience, so it´s behind a login, thus, if you want to see the actual page, let me know and I´ll have to create a temporary account for you.

My situation is this: I am a teacher and transitioning to a new syllabus, so for the next year, I am running to similar sites for different year groups. I currently use the free version of the slider to display news posts from the news category. At present, I am just duplicating all of the posts on both sites, using the shortcode

[psc_print_post_slider_carousel]

My question is this: Would it be possible for me to either enter a code in one of the sites that will actually pull posts from the other, or could I possibly create a third site just for these posts, and use a shortcode that would publish the carousel to both pages, such that clicking on one of the posts, would take you to that third site to see the post?

Any creative ideas you have would be welcome.

Thanks.