Converting Pattern from DK yarn to Knitting Worsted

I found a pattern for a sweater that my granddaughter really wants. Here’s the problem - it is done in DK yarn on size 3 and 5 knitting needles. I cannot find any KK yarn in the craft stores where I live.
How do I go about changing this pattern so I can make it with knitting worsted yarn.
Any suggestions would be greatly appreciated.

You might be able to sub sport weight on the same needles. Or regular worsted on size 8, but knit a smaller size.

What craft stores are near you? Hobby Lobby’s Sweet Delight baby yarn (which does have some darker colors) runs from sport to worsted weight. Baby yarns are usually thin, but mayber thinner than DK.