I knit up something a couple of years ago that had similar directions. It will feel weird but just do exactly what she's saying. Also, insert a lifeline so you can feel more confident about ripping back.
So your directions say:
"Purl 1 row. Turn work. Now you will begin to work straight, no longer in the round.
Purl 1 row (WS)"
If you are at the end of your first purl row, all the stitches should be purled, and you just actually turn the work around and go back the way you came. If you were working stockinette this is where you would work a knit row, but it looks like you are working a second purl row marked as WS so go back over those purls with another row of purls until you get to your marker.
This will feel weird, but it's not like the wrap and turn in short rows(I'm really scared of that). Just pretend you have forgotten you are working in the round!