Just wanted to add, I have read that sometimes animals will overeat because they are not getting enough of what they need in their diet. So they eat more of whatever is available to get those nutrients. That they will eat less of the good stuff because what they need is there, so they do not have to eat more to get it. (I cannot say this is a true, only something I have read)
Maybe try introducing a better quality cat (kitten) food with less fillers and more good proteins and she really may settle into better eating habits?
I feed Chicken Soup for the Cat/Kitten Lovers Soul dry and Nutro canned.
They eat a more consistent diet now, much more consistent than before I switched over.
Just a suggestion, espcially because she is pregnant...she really needs to be filling herself with good, high protein foods. For her health and the health of the kittens.