My sister has delivey before 2 day ago.she has baby girl. now she has a problem like she cant able to feed her?

my sister has delivey before 2 day ago.she has baby girl. now she has a problem like she cant able to feed her.lot of milk is there but not coming out.so child cant able to satisfy.pls help me in this.any homeopathic, aryuvedic or allopathic medicine.