Pattern help :)

[Blue Savannah]

I'm going to make this Lemon Squeezy out of some BFL/silk handspun by AllisoninTX The pattern calls for bulky weight, but the yarn is more of a worsted weight.

The pattern as written starts off on size 15 needles and goes down to 13. Should I just use the same size needles, or should I use 13 and 11 instead? And then maybe make it a little longer? Or just make it as written?

Ok, with the pictures I can't tell if it's a rectangle or if it's its a triangle. For me, it would be a feel thing. (and maybe if I already had the needles in a certain size) Whatever needles felt good with the yarn I had is what I would use. It's not a sweater with shaping that needs to be fitted just the right way so I wouldn't be too worried about the guage.
Wow, that was like a super wishy washy answer wasn't it? I'd like to see what other people say. I hope it turns out great for you!

[Blue Savannah]

wishy-washy is just the way I like to knit. So that's a perfect answer.

[ellies mom]

I'm guessing there is a reason they want you to decrease needle sizes so I would probably go with the size 13 and 11 needles. It will turn out smaller which may be fine or you could easily add repeats. You could knit a swatch and see how it compares gauge-wise to figure out about how big it will be and how many repeats you want to add.