OP, the school threw you a bone by giving the option to switch to RD.
TAKE IT!!!!!
There is absolutely NO downside to change to RD and it takes the pressure off having to go to this school if she changes her mind. This assumes they stand by their acceptance of her - or are they saying if she goes to RD they will have to accept her with the RD pool? If so, how are her grades + scores for this school?
Do realize that she needs to get apps in really soon if she wants to be considered for some scholarship $, as I recall quite a few schools had Dec 1 deadlines for school apps if you want to be considered for merit $.
Also, my son changed his mind a couple times on which school he wanted to attend - and he knew what he wanted to major in. Spring of senior year a lot of kids we were going back and forth trying to decide on schools. And then financial aid offers came out in Feb/March and caused a lot more changes. We did "due diligence" on schools in his junior year and early senior year. In the end he chose a school he didn't even VISIT until March of his senior year (fortunately he had applied to it on time, mainly to show that he could get there). He's quite happy at the school he chose and in the end he's where he was supposed to be. So be prepared that she may change her mind multiple times and keep her options open. Get out of the ED, apply other places, and see how the cards fall.
Good luck!