Can I make it less

Hi

I am working on a v shawl . My question is if it asks for 36 in , in measurements both the first half and second and I wish to make it a bit smaller. Instead of 36 in, what size can I do instead?

The pattern

You can cast on fewer sts and repeat the rows for a shorter length. Instead of 36" work whatever length you would like. To keep it proportional, you may want to cast on fewer sts.
You could also knit with a finer yarn weight. Homespun is a bulky so something like a worsted would make a smaller shawl overall.