If she only has 2 dinners those are actually pretty good choices - access to lots of nutrients - iron, omega 3, proteins, carbohydrates, vitamins in the tomato sauce. (esp homemade)
I think the thing with microwaving is to stir regularly to make sure that temperature is evenly distributed and there are no cooler spots. The other danger is that some adults begin eating straight out of the microwave whereas the cooking actually continues for a couple of minutes and standing is quite important. However I doubt that's your problem and you probably spend an age blowing on food like the rest of us.
I don't think it's bad for any other reason (it's actually a good way to do veggies as it retains more nutrients than if they were boiled).