Always burp the child after feeding. This will prevent vomiting. There are other reasons for vomiting in babies. Your paediatrician will be able to tell you about them.

Dear parents,          Your pneumonia finding do not correlate, pneumonia is always accompany with fever, cough, increase in respiratory rate, with vomiting, urgently consult a Paediatrician.

The commonest cause of vomiting at this age is regurgitation due to overfeeding. Give breastfeeds ONLY,nothing else by mouth,feed at a gap of atleast 2 to 2-1/2 hours,don't wake her up for a feed OR don't feed while crying,unless 2 hours have passed. Feed for about 5 mins each breast,then burp the baby for atleast 10 mins after every feed. Lay the baby on her RIGHT side for half an hour after burping and keep her elevated by placing a cushion beneath the head and shoulders,24 hours. This should solve your problem,provided you follow it sincerely. If not improving even after one week of the above,consult your paediatrician for physical examination and treatment. Although you have mentioned pneumonia,that is a VERY serious disease at this age and requires IMMEDIATE hospitalization.