Hi,
As she don't have any illness so will tell only simple things. Add peanuts, yoghurt, nut-butters, ajjwain, chawanprash, ginger, basil, mint, curd, peaches, plums, these all can increase appetite, from pediatric see his body weight height comes in normal range if yes ,then no need to worry too.
Stress,
constipation, lack of exercise, snack between meals, distraction, punishment, illness are to be avoided. Have fun with food, water before 30 mins food, replace junk, make home cool, keep devices away are helpful.
Pediatrician can see weight to height ratios and tell if there is need of meds.
Take care. Hope I have answered your question. Let me know if I can assist you further.
Regards,
Dr. Sunny Madar, General & Family Physician