miyuki-san's height is listed as 5'6 (168cm). i could not find any mention of her weight, but the average japanese female of that height usually weighs 120lbs (or 52kg) at the bare minimum. it is very likely miyuki weighs more than this, given her figure.
yet i have weighed myself today on a scale that works, and it says 109lbs (49kg). i double-checked it, but unfortunately it was true. the worst part is that i'm not even female, i am a male from the united states. my height is several inches taller than her as well.