Do you have an oral antibiotic on hand? If an egg breaks inside, the yolk almost immediately invites bacteria to grow.
Is she leaking egg yolk from her vent? Is there a watery discharge?
She doesn't need to stay long in the soak water. Be sure to give the calcium tablet though. Get a box or pet crate where she can stand up inside, and place her on some old towels to absorb the fluids she'll be losing. This will also make it easier to see exactly what comes out of her vent.
She needs to be comfortably warm and have access at all times to fresh drinking water so she stays hydrated. She can have her regular food, as well. Then keep her in a quiet place where she won't be stressed by anything. If this goes on for more than a day, she will need a calcium tablet each day.