my baby girl was fair when born now her skin has become darker what product should I use to improve her skintone

A. Hello good morning !! Skin colour changes after 1-2 weeks of birth it is normal . Some might regain it by 4-5 months, skin complexion depends on hereditary and melanin content. Use Baby hug milk soap or body wash ,due to its mild and gentle ingredients - Almond,milk proteins help in lightening skin complexion.