Sometimes mine are like this, particularly my first two who had to be talked down, literally, not to scream constantly.
Except on very gloomy days, there's constant chatter here, not yelling. I love it. If you don't, I'd separate by sex to prevent more budgies. You may wish to do this anyway, for other practical reasons.
Budgies kick their babies out of the nest eventually, so you may want to start with getting a separate cage for the baby. Do you know the baby's sex? If not, post a photo here.
Some adults won't want to be put with a baby. Also, remove any nestboxes. If it were me, I'd honestly house all three separately. They could mingle not in a cage, if they so chose.
@AussieBird @Ripshod @Lady Jane @Lori D Pert