Broken clavicle (infant)

Last night while changing our 9 month old at 3am, my husband turned around for one second and she rolled onto the floor from our bed. I heard a loud thud from the kitchen while I made her bottle. We’re away on vacation and she’s been in the pack n play, but we’ve been changing her in our bed. He is broken up about it and I’ve never seen my husband cry the way he did. It was a total accident and he has major guilt. Anyway, we took her to the ER after a couple hours of observation because whenever she moved her left arm, she’d cry. She literally never cries, so we knew something was wrong. She has a broken clavicle (collarbone) ... it’s displaced. There’s nothing they can do because she’s so little so we just need to let it heal. Any other mommies to infants go through this? How did you make them more comfortable? I called her pediatrician and she said try to immobilize it by pinning her clothes from her arm to chest, but all I can see is a sharp safety pin poking her and causing more tears. Any ideas? TIA! ❤️