At toddler age, children are very fussy eaters and will go for days without eating very much at all. They can even have a few days of healthy eating at a time. To submit to a toddler's will based on fears about their eating habits will encourage this kind of behaviour more in the future.
Your child may just be uncomfortable with her booster seat and will rather sit at her high chair.
Experiment with alternative seating arrangements.
For working parents, there is very little quiet time they can spare with their children. Mealtimes are one of the few times in a busy day that a child can actually sit on the parent's lap. She might just be missing this physical contact.
A child will willingly exploit the fact that they will eat more of their food when sitting on your lap or eating from your plate. Many parents are anxious about their children's random eating patterns and will put up with all sorts of inconveniences to make sure they eat regularly. You need to present your daughter with a few choices of healthy, nutritious food and be aware that they might get hungry at odd times during the day, instead of designated meal times. Do this at the table where she is supposed to eat and eventually she will learn to eat there without fuss.