OK, you complicated things by giving her live food, & not waiting for an answer about your early attempts to feed. One mistake seems to have been to keep offering every few days- that just makes a shy feeder even more nervous & more likely to refuse. If a snake refuses a meal, wait at least a week, & if they refuse again (especially if they're beyond 'hatchling' size), you might wait 10 - 14 days before offering again. Meanwhile, see if they might be coming into shed also- I'm quite sure snakes can "feel" a shed coming well before we can see any evidence of it, & most do not want to eat while in blue.
Another possible reason she's not eating is that she's not happy with her home set-up- & even if your other snakes find it suitable, you have to realize that they're not all the same. For best results with a new snake, duplicate the exact home they came from for a while, until they're eating reliably for you. It's frightening & disorienting for a snake to be re-homed- they have no idea where the familiar place went to or how they got here- it's scary. Might help to give more details about her enclosure- how many hides? How big are the hides? Are you handling this snake?