Our child had a feeding tube and we were highly misinformed when we opted for the option. He became incredibly dependent on the tube and it almost seem as if he forgot to be hungry and even "forgot" how to eat. In our experience, we find that doctors were so incredibly afraid of malpractice issues that they were reluctant to remove his feeding tube. We got into this terrible cycle where the tube was causing him a lot of vomiting issues and he did not want to eat, yet we needed the tube to keep him nourished.
We took a leap of faith and decided to wean DS off on our own. It was the hardest and scariest 4 months of our lives. I don't think I could have done it without my husband (who is a physician). Weaning my son off the tube was the best gift we felt we could have given him.
Baring underlining health issue that causes her to be declared in the "failure to thrive" category, you should allow her to eat on her own even if she is low on the growth curve.
There is a support group for tube fed kids that I found helpful.
http://tubefedkids.ning.com/
Best of luck, OP.