Hi Ladyearh,
It's my experience that chickens eat anything that they can swallow.
Mine have eaten glass, rusted nail heads, push pins and an igniter from the back of a bullet (that's the one that almost killed my bird). All by the way came to us in top soil that had garbage in it. Ugh, people make me so mad sometimes!
Anyway what you could try, would be to soak some bread in olive oil and let her feast on it for a few minutes (maybe away from the rest if they didn't injest any), this will allow for bulk to push through her system and she may pass most if not all.
That should work... Check the poop board in the morning to see if she is passing it (it might not be the only indicator - but it's a start).
If she declines, as in slows down her eating / drinking, or stands isolated - I would take to a vet that can do an X-ray on her to see if it's making her sick (blockage). The gizzard will clearly show all that's left behind.
As far as I know, styrofoam is not poisonous and either is aluminum. I just don't know how much she ate to cause another issue.
Good luck I'm rooting for her
