Getting in a little late on the conversation, but so long as they can dry off in a warm spot (so they don't catch a chill), there is no such thing as too many baths for a parrot

Keep in mind, they live in a part of the world where it is not uncommon to experience rain several times a day, so they are designed to handle water. Our boy takes a shower with my hubby in the mornings, every morning and gets pretty wet (not totally soaked through). Usually after lunch, he takes his own "bath" in his water dish, and he gets a good "dripping wet, looking like a drowned rat" bath about once a week using the spray bottle. Frequent bathing not only keeps them clean, but it cuts down on dander, keeps their skin moist and encourages healthy preening. Plus many bird find it plain fun, and it's a great bonding activity.
Good nutrition is also essential to feather health. If they aren't eating a healthy diet, they will have dull, dingy and sometimes patchy feathers that no amount of baths will fix. Once she is on a healthy and appropriate diet, it will takes as long as it takes for her old, damaged feathers to naturally molt out for her to start showing the benefits (which can take a year or two). Best of luck, she is very pretty already!