My 4.5 yo ds has sensory issues, major food aversions and something therapists call oral defensiveness. At 2.5 yo he ended up in hospital w/nutritional deficiencies. The Drs told us he'd require a feeding tube. He had HORRIBLE reflux as a baby but his ped said it was w/n the normal range and didn't recommend any treatment.
I'm not saying that any of this will happen to your child but I know how difficult food issues can be. Some of the things we tried were occupational therapy, feeding programs and I took my son to a ped GI Dr to make sure he wasn't still experiencing reflux. None of these things worked very well for us. Instead I have come up w/a smoothie that contains all the vits and mins, protein, fats (EFA's) etc that I could stick in there and slowly, very slowly my son recovered from the deficiencies and he is VERY SLOWLY adding foods to his repertoire.
My son also still has the gagging reaction to a lot of foods but it is lessening. I don't push him to eat because it doesn't work. It backfires. The ped GI that saw my son said that if a child doesn't have any physical GI probs, eventually 95% of kids will outgrow their problems. They may always be slow to try knew things and they may not want to eat a variety of things but they will overcome most of their aversions. I've learned to go at my son's pace.
I'd recommend finding a vit/min supplement that your dd can take and try to get her evaluated by early intervention. EI is available usually to kids under 3.
HTH a little!