i think using the highchair and safety belt so that they cant jump out plus no tv no toys no nothing is the right method。。。。。。
four year old is old enough to manipulate you so dont encourage her eating by giving her new toys。。。。
i think you can also implement some penalty if she doesnt eat by herself at the meal time at the dining table but not.letting her pkay certain toys tgat she likes.。。。。
you are on the right track but just dobt give in enforce strictly plainly and calmly。。。。。