Many regular vets will do a fecal float for worms and test for cocci if you bring in a sample. Be pushy, sometimes it helps. If you can't get one checked, I might put her on a 5 day course of Corid (amprollium) 1 tsp powder or 2 tsp liquid in 1 gallon water. Or give her Di-Metox or Sulmet . Here is the thread on tube feeding: https://www.backyardchickens.com/t/805728/go-team-tube-feeding