Dp's just suggested Elsa dresses for the girl's dolls as an extra something to unwrap. I've never made dolls clothes & I don't think the only place in town to sell (an incredibly limited selection of) sewing patterns, had ones for dolls clothes.
I have fabric to use that dp's aunt bought me, just not sure where to start with a pattern to work from.
I've made some simple Elsa dresses with a sleeveless vest top, gathered skirt and open back with velcro fastening. If you've got dresses that fit them already you could trace the bodice back and front (minus any sleeves) and then just add a gathered skirt. Don't forget to add seam allowances. Make it up in kitchen roll first to check dimensions and fit.
Dolls clothes are always a big hit in this household - even my ropier concoctions are much-loved.