Mine has a traditional palate expander, actually hers is a newer version called the "mini" that is very compact (look it up) and it took her all of one day to get used to it. She can eat everything (although avoids what the orthodontist told her to like sticky/chewy/etc.).
What 15:40 describes is highly unusual, it sounds like perhaps her child has some sensory issues, the palate expander should not affect a child's ability to swallow, it's at the roof of the mouth.
Pics of traditional vs mini