Changing yarn weight

I'd like to knit a Genevieve, but the yarn I want to use is DK not Worsted. I have a tall, skinny 3 year old. I plan to knit the 4/5 size, and maybe add length if necessary - has anyone tried this? Should I stick to the needle size recommended in the pattern or the size recommended for the yarn?

I also want to knit a shawl for my MIL, I have the whippoorwill pattern, which looks lovely, but the yarn I have is worsted - again, this won't make a difference will it?

I did a Something Beautiful shrug for Bella in DK, but I knew I could get the gauge I needed with certain needles. Can you get the required gauge or do you need to do some maths?

My concern with the Whipporwill is that it's written for fingering, so doing it in Worsted may make it a very different shawl. It will affect the drape etc.

Yeah, I think Worsted to DK might be more easily doable than Fingering to Worsted!

Regarding the Whipoorwill, i have just checked the Rav projects page for worsted and it seems if you use 5mm needles and do the small size you should get a nice quick knit, not sure how many skeins you have to play with here, but using a thicker wool will mean you need more skeins for the project.

Yeah, I'd be surprised if you needed to change much at all. If it was me, I'd do it using the needles stated and the size I actually needed.

Have found another pattern which I think will work better in the yarn. Will just have to get more fingering weight yarn and make the whippoorwill for myself!