New to weaning

Do babies instinctively stop eating when full? We started weaning a week ago, I have puree'd some veggies and frozen them. I heat 2/3 cubes depending on the size and then I feed her but I stop when I think she has had a good enough portion. She doesn't show signs of being done though but I worry if I let her keep going she will have too much. It doesn't help we are weaning from breast milk to formula at the same time.