Expert opinions needed -- yarn weight substitution

I am about to start a new project and need a little advice from my best friends and advisers on all things knitting!

This is the pattern I am going to use:

However the yarn that my mom has her heart set on is here (look for “Concha” at Ewe Knits

Now… my question is…Since this pattern is not fitted, do I simply knit it the same and not worry about the size? Do I knit with a smaller set of needles? Do I convince dear sweet Mama, that I can’t do that pattern with that yarn? I am very new to knitting. I have done a lace pattern already, just not sure about such a big substitution.

Thank you to anyone willing to help!:inlove:

The yarn in the pattern is laceweight, the Concha. If you knit the pattern on smaller needles you’ll have a very stiff wrap. You could knit the wrap on size 10½-11 needles to get the same lacey airiness of the pattern, but you need to cut down the number of stitches or pattern repeats unless you want a very large wrap. It looks like the wrap is a mobius style, do you know if it’s knitted as a rectangle then sewn edge to edge? If it’s a rectangle then using the larger needles and yarn will make it about twice as wide, and you could probably just go until it’s the length you want.

Thank you Sue. It is knitted circularly. 6 stitch multiple; 6 rnd repeat. The instructions call for 300 cast on stitches. Then "taking care not to twist sts, join into a rnd. (place marker) Then repeat until desired length and bind off. So, would I want to cast on 150? I know it may just take swatching, but I really don’t know how to look at a swatched sample and calculate how big it will be. (And one other thing…it calls for using a size 2 needle for the majority of the wrap, (I don’t even have a size two in my circulars) will that size work for worsted weight yarn? Do I need to plan on making it with such a large size needle (10 1/2 or 11) as you suggested?

Thank you again to you (Sue) and to anyone else willing to try to figure out what I am talking about!

You certainly can’t use the tiny one called for by the original pattern on worsted and lace is usually done on a needle 2-3 sizes larger than you would normally use. Knit up a sample using various needle sizes, and you will see both how the yarn looks in the pattern to choose your needle size, and how many stitches you will need to CO, multiplying the sts/inch times 63" which I think is the finished circumference of the whole thing. Probably 200 sts would be right, as I think 120 sts would get you only about 40" or so.