It's a bit hard to read the label in the picture (reflected light is a nuisance when taking photos!)
But I'm pretty sure it says the medication is monensin sodium at a rate of 125 mg per kg of feed.
I'm not familiar with that particular medication, so I looked it up.
I find lots of sources-- including the bag you have-- that say not to feed it to laying hens.
I tried to figure out the reason (danger to people eating the eggs? danger to the hen herself?) I cannot find a specific length of time to avoid eating eggs from hens that had that medication.
Regarding health of the hen, I did find this article:
https://www.tandfonline.com/doi/pdf/10.1080/03079459408419027
Title is "Monensin toxicity in two breeds of laying hens"
Authors Y. Weisman, E. Wax & I. Bartov
Published in 2007
It says that higher doses of monensin will cause hens to lay fewer eggs, and will cause some hens to die. The dose in your chick feed is about the point at which the study found it to be fairly safe.
There is also some discussion of that medicine in this older thread:
https://www.backyardchickens.com/th...-laying-chickens-and-safe-to-eat-eggs.844615/
If you have access to non-medicated chick starter, I would be inclined to use it instead. If this is the only chick starter you have, I would probably use it, and let the hen eat it too, because it is not really practical to feed a hen one feed and her chicks another feed.
Have you done this before, with this hen?
Most hens need to sit on eggs (real or fake) for a while before they are ready to accept chicks to raise. So if the hen has just now gone broody, she may not be willing to adopt these chicks when they hatch. Of course you will not know for sure until you try it. Some hens will accept chicks much sooner than other hens, and your might be one that will.
If the hen is not willing to accept the chicks, you will not have to decide about whether she can eat this medicated feed. But you would have to brood the chicks yourself.
