Factory Default your roku to clear out whatever settings you have,
I wouldn't do that. It will unlink all your accounts and you'll have to start from the beginning. Just go to your Amazon account and unlink your box, then go to hers ( or set up a VOD account for her if she doesn't have one) and link it there.
No, I don't work for Roku.
Netflix Player N1000X, XDS 2100X (premature death by lightning)
Roku2 XD 3050X, Roku2 XS 3100R, Roku2 4210R