Give her saline nasal drops three times a day Check her body temperature with digital thermometer If fever is there give colpol drops If still she is not drinking/eating please undergo an offline consultation

May be due to cold she might be avoiding milk you have to again reassess the position and attachment while giving breastfeeding. also check the oral cavity of the child for any ulceration or teething problem /pain which might be causing pain. if the child is ill or is having fever /abdominal pain / vomiting and loose motion then also the child may decrease the intake of food as well as milk. after ruling out such problems if the problem continues it is advisable to take a medical opinion