I suggest you get a plastic baggy, and instead of filling it with Cheerios, put in bits of corn or chicken breast, green peas, or small pieces of cooked carrots so if the child refuses dinner, who cares, because the child has already had good food. She drinks whole milk just fine. Do that for about a month. Don't try to make the transition overnight. Some children gag and vomit when they taste something they don't like.
Some children do the same with green peas.
Many of us have food aversions too. The approach must be very gradual if you want to correct it. The rule of thumb is approximately one ounce per day for the first six months and then one-half ounce a day the second six months of life up to a year. These are just rules of thumb and babies come in different sizes. There are genetic factors that must be thought of too.