How many pounds is three stone?

Adele has observed one year since
her divorce from the father of her son,
and during that time,
whatever else she has been up to,
she has reduced her body weight by 'three stone'.

I should not think of ill omens,
but this reminds me of Maria Callas,
who when she started singing dramatic roles
was enormously overweight, then stripped the overweight off.
And lost her singing voice
-- she did this comeback tour,
wearing hugely expensive gowns,
looking like a fashion model or something,
and sounding absolutely awful.
God forbid that history repeats itself ...