I know, they are so tiny, it's hard to see. Having a helper would be good.Best I can tell her vent is open I’ve watched her have some water poops nothing that looks normal or solid yet. As small as she is I think this is the navel I’m having trouble seeing with the swelling and her squirming. Looking at the picture again it appears something is coming out
Look at her tummy. I'm afraid that her navel is open. If it is, then clean that with an anti-septic (chlorhexidine, betadine if you have it). Apply triple antibiotic ointment or bacitracin.
Sometimes if the navel is open they can get infection, the chick may fail to thrive (more is wrong with them/developmental issues). Sometimes that heals fine.