DON'T MESS WITH MY HEAD CANON.
But in all seriousness, I did check the wiki. Apparently, there's an official novel of FE7 and Ninian died of illness. Oh wellz.
She looks as old as Tiki in FE:A.
What always bugged me was the whole "This world's air is different. You won't live as long" Bullshit. Everyone takes it to mean Ninian died like...not long after. I always took it to mean "Hey, you won't live as long as a dragon normally would. You'll have a human lifespan."
Speaking of school, my final is tomorrow. For the last class I need to take before I get my Associate's Degree.
I first joined in FE4 Thread antics during my attempt at university and now, 4 years later, I'm getting a degree. Shit does time fly.