My baby has chubby cheeks and double chin. Therefore, her neck area always become red and sweaty. I don't know what should I do. Can anyone advise me?

No matter baby is little healthy or not, the area around neck does form layers and one has to clean in between the layers during the initial months and gradually when the baby is able to hold his head the layers also open up. During the day, you will have to wipe the neck area with alcohol swipes so that there is no fungus formation. Keep the area as clean and dry as possible. You can apply baby cream, and then dab it with baby wipes so that there is apt amount of moisturiser left.