Laviani is very simple triangular shawl. The textured pattern consists of repeated 4 rows. You can vary the size in any way you want: you can stop and proceed to border of garter after each third of 4-rows sequence.
I would suggest a fingering yarn but you can vary. Just need to mention that use of thicker or thinner yarn can possibly affect the final size.
If you have any questions please do not hesitate to contact me.
Happy knitting!