WAAA!! Such a good sad story. I read this like 3 or 5 times. I wonder why she died...

If you looked at the part with the wings, you'll see her head under water, indicating that she drowned and also picture near at the beginning showed that she was a swimmer at the time as well

Not really, she died from cancer. When you look at one of the pages there's a doctor's recipe in which there's the prescription for a cancer medication :(

Thanks for the explanation