At her age its best to get her admitted if the problem is severe, Even in a small hospital for the time being. If the vomiting is severe and she is not taking any food or liquids orally she may need IV fluids. The photos you posted only give part of the problem and she needs further investigations like electolytes. For now atleast give her ORS tetrapacks to correct the electrolyte imbalance if any, due to the vomiting. She needs an endoscopy and further evaluation. We have seen multiple cases of that age with those symptoms and they mostly always need an endoscopy. Cant comment more than this.

She needs evaluation at hospital and possibly admission, corona dose no consider other problems, at this age with these findings ,are more harmful ,if untreated