So I figured out why my stitches were going diagonally. I was doing the knit stitch wrong! How did this happened?! Did I learn it wrong? Or subconsciously modify it? I looked up the purl stitch and it turns out I was purling wrong too. Not way off, just slightly so that in non-round straight stitch it didn’t seem to matter; I guess the two mistakes just canceled each other or something. But when I did all knits round and round, it came out diagonal. So at the ankle of one of my sisters new socks there is a line where you can tell that I switched stitches and where they suddenly start going straight. Its not obvious, especially from a distance so I don’t think it will matter. Anyway, thats an interesting lesson learned!