Yesterday I had 2 chicks die and this morning I find one dead and a mother lethargic and not eating so I’m trying to get her to eat some egg and she poops
It won’t hurt to treat with corid. Dose is 1.5 tsp per gallon powder for five days then half a tsp for another week or so. No vitamins during treatment. Start them on it now while you’re waiting for other opinions.
If you suspect coccidiosis then I would start treatment ASAP. Treating with corid won't hurt them even if it's something else, but coccidiosis can kill. Get them on Corid medicated water ASAP, and any that are acting sick or lethargic give an oral dose to as well as the medicated water. Dosing for that is here: https://www.backyardchickens.com/threads/corid-oral-drench-instructions.1211991/
If the mother isn't drinking give her some of the medicated water mixture as well several times a day orally, until she's drinking on her own. You have to get it in them for it to work.
The dosing in the post above (1.5 tsp) is correct for the powder form of Corid, if you have the liquid form the dose is 2 tsp per gallon of drinking water.