You are letting this turn into a major drama complete with a possible power struggle.
The more you try to force, beg, plead, order or cajole her to eat; the less likely she is to do so.
If there is nothing medically wrong, then I suggest you stop making a big deal out of it. Fix the meals you would ordinarily fix. When it is time to eat, she should sit at the table with everyone else. If she chooses not to eat, she can sit there until the meal is over.
Then she can choose whether or not she wishes to partake when it's time for the next meal. Don't fix her something separate or offer snacks.
Unless there is a medical cause, she will most likely eat when she's hungry - especially if there is no longer any dramatic attention attached to the whole thing.
