Of cause the oldest sister also needed/wanted (or actually got, as I wanted to knit one for her) a cardigan. This is a bolero from the book Knit for Kids by Paula Hammerskog and Eva Wincent.
It is originally in alpaca and Kid silk but I made it in Allino (linen and cotton mix 50/50) and kidmohair.
I've found that warm sweaters are not used that much so thinner cardigans are far more popular by both daughters.
Today I'm a happy mother and a proud knitter.