George gave you great advice. Birds have a dry mouth so hot, spicey foods don't bother them. You can add cinnamon to her banana and apples, any spice we eat you can add to her food. You might want to consider adding a small amount of sunflower free seed to her diet ( about a teaspoon and a half) as this would be what she eats in the wild. Yes, some seed is good, a good seed is Sunscription as it is human quality. You might also want to switch her to a quality pellet such as either Zupreem or Roudybush which is more nutritious due to the way it is extruded when made.
Sweet potatoe, squash, kale, carrots, pasta and beets are also good foods to try. Never feed raw potatoes as it could kill or make her sick. Many folks cook a mash that includes beans, and veggies and they freeze it, some add greens and cooked pasta to it just before serving. Use ice cube trays to freeze the mash, pop out the cubes and put in plastic freezer bags to save room, and take out what you need for the day, heat add whatever you'd like and serve.
As George stated, keep trying different foods, it'll seem that you waste more than she eats, but with birds presentation is everything. One way to get her to try a new food is to roll a new food in a bit of seed. She will get a taste of the new food when she bites into the seed. Almond butter is also good for her.
You are off to a great start!
I'm so glad to hear that you are doing so well in her care and up-bringing!
