Give her the calcium now. It won't hurt and it can save her life if she's low on calcium. The reason is that if her blood calcium is low, as her egg hits the shell gland, if the gland is low on calcium, then it draws on the calcium in her blood, and that can deprive her heart of calcium needed to keep beating. This is called sudden death syndrome, and it's preventable if you give the calcium now.
The calcium will build a shell, but it also causes contractions to make it easier for her to get the eggout.
The calcium will build a shell, but it also causes contractions to make it easier for her to get the eggout.