Crumbled is always easiet for bigger birds to digest...it is messy and there is quite a bit of loss, but for our bigger pet birds it's worth it to go crumbled.
Once they're over 10 months old, even though laying, its best to drop protein level of feed to prevent health issues.
Always provide oyster shell or some type of calcium.
I only have Chicken and Guinea, but you did all you could with prolapse.
Warm water sits, I use regular canola oil or baby oil as petroleum jelly can ( not always, but have seen it) cause poo build up and constipation. It just collects and during fairy lays mixes or "grabs" the soft shells and can cause more issues.
Don't understand how it why, but jellies seem to create more issues, stick to oils.
She may have had constipation (high protein feed not drinking enough water) and a soft shell (fairy) caught up and couldn't pass.
While there are two ducts there is only one vent and trouble galore when there are digestive issues.
God bless, keep loving her, she's still with you I believe.
Have had a bird or two linger for months after passing over.
Go ahead and laugh y'all but when you feel the weight if a bird plop on your bed, hear pecking and Pittty Pat of bird feet where there is no bird.... I'm a believer

Peep was blessed and so are you to have had each other for her short life.