This is not vomiting
but possetting. In all babies this is there due to lack of strengthening of a muscle where food pipe joins stomach. By 6 months to 1 year this problem will be over. After feed, you burp the child by putting her on your shoulder or on the thigh with stomach pressing on your thigh. You keep monitoring weight every month and you will be happy that all feed have not gone wasted! for regular advice on child rearing you ask privately and be in touch with me as your personal doctor. Regards.