My sister wanted to purchase some stuffs on the app so she created a new apple ID. I change back to my apple ID on the settings while I'm using it, but when my sister tried to change it back, the purchase was gone. The apple ID logged in was hers but the apps are under mine(i could tell when im trying to update my apps) I downloaded the app and she made purchases in the app, technically its still considered under mine? Is that why? What's going on and how can my sister can back her purchases on the app??