Classic egg bound behavior will include straining on the nest, hesitation to get off the nest, huddling, and the common penguin like walk.
I don't let a bird go long being egg bound. If I note a bird is struggling, I obviously give them some time as NO egg laying is comfortable, per se. Many birds strain a bit to pass an egg. However, if she seems distressed and overly long for a number of hours, then I intervene. I wouldn't let an obvious egg bound situation go beyond 24 hours. Give her time (6 to 8 hours), then intervene.
Holding her in one arm while gently palpitating her abdomen often does the trick to help it pass. That's the best method. She passes it herself. If she can't get it out, then you have to bring her into the house, submerge her in warm water, and see if that helps her pass it. Usually sitting in the warm water does the trick all on its own and it relaxes her muscles.
Last resort is to try to gently, carefully break the egg inside her, so she can expel it. For obvious reasons this is a last resort as you can harm her, and it can be difficult to get all the pieces out.
Hopefully she will be able to clear it soon.
Be sure she is getting enough calcium. Good hard shells help eggs to pass. If her shells are soft at all, they will more easily get egg bound.
My thoughts.
LofMc