Please Help! Need Yarn Help

I’m a knitter that can make scarves, dishcloths and some blankets. I have a friend who has some of her grandmothers yarn and wants me to make a scarf. It is Bernat Cott’n Silk. It says 50 grams, 75% Cotton, 15% Nylon, 10% Silk. It also says, In stockinette stitch, 5 stitches and 7 rows=1 inch on size 6 needles. I’m not great about knowing yarns but this stuff is awful. No give and the thickness varies through out the skein. It’s a mix of white and light blue. I thought I would match it with a white yarn and mix it with hers. Maybe a pattern that knits some with the white then I could use hers for a couple rows as an accent. I am thinking though that I need to be careful on what kind of yarn to put with it since it’s such a thin yarn. This is where I have trouble. There are TONS of yarn out there, how do I pick. I would think it can’t be to thick. Any idea’s or suggestions? I live in a place where the nearest good yarn store is over an hour away. I have a Michaels but have yet to find someone in there that knows much about yarn or knitting. I sure do appreciate any help. Thanks so much!!

info on that particular yarn is here: http://www.ravelry.com/yarns/library/bernat-cottn-silk

and it says it’s actually considered a worsted weight (medium, #4), although there’s a whole other discussion going on in another forum about the differences between MFR A’s worsted vs MFR B’s dk weight, etc. but the reason for the thick/thin is because it’s a novelty-type ‘nubby’ yarn, it’s on purpose. i’ve been told when it’s that kind of thick/thin yarn, the weight is listed as the average of the two thicknesses.

that link even has some pattern and project ideas. because of the thick/thin aspect of the yarn, you might just stick with a 2nd yarn in standard medium weight (#4, worsted, aran, depending on packaging). some ideas for great scarves are at http://www.ravelry.com/patterns/search#photo=yes&craft=knitting&view=captioned_thumbs&availability=free&sort=created&pc=scarf&page=1 and most of them could be knit with 2 strands held together, provided you adjusted your needle size and stitch count…

Thank you!!!