I had picked up this yarn at a thrift store months ago, no idea what it is, looks like heavy worsted weight. I used 3 fist-sized balls of it, holding all 3 together as I knit.
I modified this pattern by: cast on 35 (my hope was the odd number would help add to the point at the back) knit for 21 rows did 3 needle bo on RIGHT side, which gave it a line down center back, and a bigger point in back too.
and my DD! Thanks for posting this!