|My SIL had this problem with her son ( now 6) and he actually landed up having a sensory problem...but it was only with his mouth. He was only drinking formula and would lick the salt off of chips. He is fine now, but it took A LOT of work.
The doctors kept telling her not to worry, but she felt/knew something wasn't right. They landed up in Philly in some center that deals with kids and eatting issues.
I hope this doesn't scare you, I am a firm believer that mothers intuition is the way to go.
I agree that she should put the dog away (out in the yard) for awhile while she has a snack tray out. I also agree, and told her, that she should just stop talking about food to her dd completely. She should have it out and available, and mention it once. "Dd, there's some food here if you'd like it." But she needs to stop with the, "Open up! Here comes the spoon! Please eat. You have to eat. Please. Just one bite. Come on." In fact, she should stop with the spoon completely and give dd autonomy in choosing whether to eat or not. It's turned into a very unpleasant experience, and it's never good to have such negativity surrounding food and eating.
She's just so stressed, but not so willing to try something different.