I have had a slow eater with me for 1.5 years. It is a much bigger issue that her parents won't acknowledge. She is almost 4 and still holds food in her cheeks, and can't chew or swallow the most basic foods, and often vomits. She definitely has sensory issues and low mucle tone in the cheeks and mouth. My 12 month olds will polish off the same amount of food in less than 1/2 the time. Basically, she eats like a bird, as I can't have snacks and lunch lasting 1 hr each. It would literally take her 3 hrs to eat 2 small snacks and lunch, and my schedule was turned upside down as a result. Now she eats next to nothing, but stays in our timed schedule. It's a tough battle to win, and I give up making referral suggestions to her parents.