Have you ever given your hens yogurt? If so, I just dip the tablet in yogurt and hold it out in the palm of my hand and the pullet/hen more often than not will just eat it.
If they don't, I sit on my knees, stuff the bird between my thighs and hold her body with my thighs and her head with one...
Very much so.
She had probably been working on passing it for a while.
You should give her a 200 mg calcium citrate with D3 twice daily for a week to help her start laying shelled eggs.