Depending on how many seniors you have and how far away they might live, perhaps you can have some sisters do a drive-by congratulations. Have a few sisters go to the senior's house and do the sorority chant while holding up signs or something. Obviously someone needs to let the senior know so that she can be home for the drive-by and maybe her family too. Then you can post the video clips to the social media feed. It doesn't have to be the whole chapter - maybe members can split up in teams of 4-5 girls who live locally to certain seniors. One of the members needs to be do the video though.
