I'm not sure why no one has pointed this out yet, but are you making sure the f/t is good and warm before you offer it? Ball pythons hunt by heat. If you aren't getting her attention first, then heating the food up really nice and hot and then offering it, I'm not surprised she won't eat. The whole " drop in a thawed rodent and wait ", is the reason why most pet shop snakes won't eat.
Take her hide out first, heat the food up really good and hot, grasp it with tongs and offer it. Chances are, she'll hit it hard and fast if you do it correctly.
While it would be a little bit of extra trouble to get a small plastic critter keeper and fix it up to hold a couple of mice, if heating the prey doesn't work you have no choice. A baby this small cannot go without food for long. It lacks the metabolism to deal with long periods of fasting. You will do permanent damage if you don't feed soon. You can buy three or maybe four mice at one time, feed them lightly and offer one every 5 days to a week. That will keep the number of trips to the store to a minimum.
Gale