I wanted to knit this sweater for my daughter but it the pattern only goes up to size 4: http://elann.com/ShowFreePattern.asp?Id=138024. I found this similar pattern, that has larger sizes, http://www.berroco.com/exclusives/polkadot/polkadot.html. Both call for worsted weight yarn but the two patterns have yarns made of different fibers. Is it ok to use worsted weight yarn that is not the same fiber as what is in the berroco yarn?
Sure any worsted weight would work. The elann pinwheel pattern is very easy to size up. Measure your daughter from shoulder to shoulder, when the diameter of the sweater reaches that measurement, then do the armholes. After that, keep knitting as the pattern instructs until it’s large enough to go around her and maybe overlap a little. I like it because it’s worked from the center out, the berroco pattern is worked from the outside edge to the center, that’s a lot of sts to cast on.