You can try giving her some nutra drench, you can give it to her concentrated if you have it. It’s mostly molasses and full of vitamins as well. It’s a specially designed for poultry. It’s good to have on hand. You can also try feeding her some egg yolk mixed with a little bit of water as well.
if there is any sign of blood in her stool she could have coccidiosis if she was not vaccinated for this or if you are not feeding medicated feed. This can be treated With Corid.
I would also post your concerns on the thread that deals with the health of young chicks or care of chicks you might get more experienced folks to respond that way.
good luck and let us know how she is doing!