I dont think you should be offering your food from an animal you just aquired to any others. That is a HIGH risk of contamination. You have had this animal for only a week. I hope that you do practice quarantine, and should probably hold back offering your already settled animal anything that has been in the enclosure with this new one. Along with that, have separate cage furniture and water bowls etc. It would be best if this new animal was in a different room all together, but sometimes that is impossible. Always wash your hands inbetween handling different snakes
As for the original problem. Snakes are all different. I don't see what the problem is having a ball python act like a ball python. These are very shy timid creatures that would rather hide in a burrow, than be handled and in the open.
Follow the advise from earlier, it is usually a good idea to let new aquisitions become familiar with their surroundings for 2 weeks. No handling, disruptions, peekings. Just change the water once a few days, and try to minimize the stress put on her, make sure that your husbandry is spot on!

You can offer her a ft mouse after 2 weeks of alone time. Do the zombie dance, if she doesnt take it, leave the mouse in over night. I have a few animals that wouldn't eat until the room was pitch black, and quiet.
If she doesn't eat, remove it the next morning, and only check on her to change water, substrate when soiled. and repeat the same thing after 7 days. Feed late at night, offer ft, leave in over night.
If you can tell that she shows no interest in FT, try a live one. The extra stimulation usually spurs them to eating.
Remember, we want her to eat before you should worry about handling her. Handling will only stress her out and prolong the fasting, so it should be at the very bottom of things to do. I hope that helps~