Advice for Social Media Director

Hey guys!! I need some advice!

As the title says I'm the new social media & marketing director for my sorority and I manage all of our socials! I am so excited for this position, however, I'm having a huge issue with girls 1. Not sending in photos, 2. Not responding or sending in photos for their birthday posts and then getting mad about it, and then 3. Not responding to our google forms for instagram posts and stories like 'why I chose this sorority' or travels and things like that 😭 any help lol?

Also please if you've been in this position before can you share how you expanded your chapters social media presence? Our chapter is really struggling and smaller than the others around us. We are in a big SEC school and I've done a lot already (changed the layout, posted differently) but I want to do more so any help would be very appreciated!