Living in Florida and since my daughter started school I give her a bath or shower every night (it is still hot out here, like 80 degrees during the day). If we are just hanging around (inside in the air conditioning) the house on the weekends I give her a break on Saturday night.
I do use California Baby soap, conditioner and lotion, they are all natural with no chemicals so I don't worry about using them everyday. When I lived up north she would get a bath every other day unless she was sweaty, dirty or just out of the pool. Kids don’t really need to bathe every day until the teen years when the hormones start.
Try brushing out her hair every night and change the pillow case often.