[~+~]
There are rumours that the songs "Hello", "I Must Be Dreaming" (Also known as "Unknown"), and "Like You" are about her sister.
There may be one or two more, i'm not sure.
I don't see any clear rules on this guild saying not to talk about it, but i know another guild has, so, as to pay my respects, i will just say what i know and won't look into it any further.
Basically, Amy was 6, and Bonnie was 3, and no-one knows the cause.