no, she will not get better on her own. This is likely a deep seated bacterial infection. It is not like a human cold virus.
The fact she us also quiet shows how sick she is. Burds do everything to hide how sick tgey are.
Fruit isn't as important as veggies. But diet alone won't cure her infection. It isn't lightly that I say you need a veterinarian . As sudden death can be the next step...birds rarely go through "sick burd" symptoms and when you get classic "sick burd " symptoms they are usually 48 hours from death. If you treat her now less expensive higher chance for quick recovery...
I've trimmed my grey's beak by a small amount myself without problem (3mm). I'll just leave hers unless it gets longer, it's been the same length for a year. Since I've started putting fresh branches in there, they've been destroying them rapidly, but I'm not sure if that's both of them or just her partner! If I'm worried I'll set up a camera to watch.The Bill structure, both upper and lower appear a bit on the long side. Just barely in the area of 'needing' attention. It is nice to have a laid back Amazon, but with a lack of interest in turning big things into tiny bits, this can be the results.
If the interest continues to be on the 'lack of side' you are likely faced with a regular trimming of the upper and lower Bill structure. Assure that you have only a trained Avian Profession complete the work as a bit to much can result in pain and not eating.
Well I'll keep an eye on her, but what you saw in the photo was most definitely pear all over her face. Messy eater.Unfortunately you will get intermittent discharge, many times missed by owners. Or even no drainage ...
I have decades of experience with sick birds. And I'm using my experience to help you. I feel pretty confident that your bird has a health issue..especially with back story.
When you ask for advice you don't always get the advice you want. But hopefully this thread will help others.
Worrisome advice from vet. Plenty of counter advice out there.
Best of luck to you