Welcome to our family, we have a welcome room, we'd love for you to post an introduction in.
It is wonderful that you are taking the initiative on helping your granda's bird.
They are often very scared of new things. So maybe just leaving a new toy hanging around near her cage for several days or more, will help her to get used to it. If you make a big deal out of it, and pretend to play with it, that helps as well. In the meantime, give her whatever she likes to play with. Does she get any out of cage time? She needs that as well.
As far as her diet, introduce her to foods that you eat, and hand feed them to her as you are eating them.Good luck, please keep us posted.