Usually doctors dont want you to start solids any earlier than 4 months, and they prefer that you wait until 6 months. In josh's case it was different, because he is such a big boy and he wasnt getting everything he needed from formula. I would wait and ask your doctor but they will probably say no. In general, your baby is supposed to have doubled their birth weight, be able to sit with support, and have lost the tongue thrust reflex. And by 3 months, josh had accomplished all that. But I don't think jaydyn has doubled her weight, i'm not sure about the other two. And you wanna know a little secret? Cereal really doesn't keep them full that much longer. And it doesn't help them sleep through the night. Josh still has 6-7 bottles a day plus his cereal, fruits, and veggies. So just ask your doc! She may want to evaluate jaydyn a bit at her next appt before she says ok.