Is it just dry skin
or you see scales along with itching? If so she might be having atopic dermatitis
. in simple words its allergy
that affects the skin and may run in families. You can have it checked by your pediatrician
Yes, you can do oil massage
. For babies Olive oil or coconut oil are better.
Yes, you can use soap. Avoid the ones that cause dryness. Oilatum soap is better for dry skin.
Yes, you can use skin moisturiser. Atogla lotion will be good. The same can be applied on the face. No separate face creams are needed.
Yes, you can use shampoo. Normal baby shampoo will do.
Hope you find my answer useful.