Sometimes the ending of a life is necessary, which also very upsetting.
As long as she's happy, care free you can enjoy her for as long as she's loving life.
Illness in a chicken can trigger other problems later on sometimes. I have a Brahma with an immune disorder, that we have to put down. She's not a good layer since she's always sick, & lay puny eggs every other day. I also don't want her to suffer with the disorder she has.
I don't know much about it either, but it does cause the abdomen to expand to uncomfortable level, & will cause pressure on her other internal organs over time.
How does her belly feel? Her body won't absorb the eggs if there's an infection.