Thanks for writing us with your health concern
I can understand your concerns. The skin lesion appears unlikely to be a bite, at least from the photograph. It appears to be infective with a clear ring of inflammation around it. Whether it is staphylococcal or not is difficult to ascertain.
Skin infections in this age group of children are most commonly caused by staphylococcus or streptococcus. Topical antibiotics may be used for superficial skin infections such as pyoderma. Systemic antibiotics (oral or parenteral) are indicated when the skin infection is deeper or there are systemic signs such as high-grade fever, toxicity, etc.
I would advise you to start broad-spectrum topical antibiotic such as bacitracin or mupirocin or similar preparations available in your locality. You can review with me a clinical photograph in another 24-48 hours.
Wishing her a speedy recovery.
Dr. Saptharishi L G