Ear piercing. After a month or two.

Hi doctor, Did gun shot ear piercing to my three years old baby girl today...at cloudnine in sterile manner...I hv come to know tat gun shot cause tissue damage...already she got infected well n v did tat in a jewellery shop n removed jewel n made it to close when she was around 8 months old due to poor hygiene...NW got pierced abv tat scar...same gun shot but sterile...when to change the starter earring after a month or two...shld v hv to rotate or push back n forth or just to leave it as it is...any ointment to prevent infection since she had already got infection I m feared...inverness ear piercing solution has been given to pour back n forth of ear lobe...hw to put drops...just abv earrings or shld push front n back n to pour...