Hen not eating! TUBE FEEDING QUESTION

[WiddleChix]

hi so I just started tube feeding my 2 year old hen because she is underweight and not interested in food along with being lethargic with a pale comb.
I just wanted to know if I could accidentally injure her if I inserted the feeding tube in too far?
I’m using a piece of aquarium tubing and used a lighter to smooth the end of the tube.
Thanks

 

[WiddleChix]

I’m also unsure of why she is acting like this. I checked for mites but didn’t see any. I also felt inside for an egg or broken egg and found nothing. Her wings droop and she has low energy, I had to tube feed her this morning because she is so thin and only pecked at the Kaytee Exact that I made her.