Beautiful egg!
OK have you had her the whole 8 months?
Grit could pass through if there's already some in the gizzard. Looks like it's almost untouched, possible it had fallen in bedding and got scooped up?
Quite a bit of mucous in the poop. I see one red spot...probably intestinal...
I would see how the crop is this morning and what the poop looks like.
I agree, sometimes you do need to separate a bird to get them on track. Generally I leave mine with the flock and just treat them during the day. Early morning while roosting, then while roosting at night if it's a...
How old are they?
If you think the grass is through, then I would give her a small amount of wet soupy feed. A bit of egg is ok too.
Grit is needed to process foods/materials, so...up to you whether to provide a little free choice for her now or wait. But I would go ahead and put some out...
When are you checking the crop?
I would not vomit her. I would treat for Sour Crop and probably de-worm her.
Make sure she's got poultry grit (crushed granite) available. Do let her drink and I would let her eat.
Do you feed your birds grass or do they forage their own grass?
What's the...