It's not imperative that she goes onto a pellet diet, my four greys eat seed, fruit, Veggies, pulses & a whole host of things like rice, pasta etc...
You will have to just keep offering them to her, try soaking them a little to soften them up, always offer new foods to your grey in the mornings when she is at her hungriest.
Here is a link for offering new foods..
http://www.greyforums.net/forums/bird-food/53831-tips-for-getting-your-grey-to-eattry-new-foods.html
Please have a good read through the various topics in this bird food room .