When teaching a beginner how to end off I don't know if it would be good to have the person ch 1 before cutting and pulling the yarn to end off or just to pull the loop on the hook without the ch 1 to end off. I've done it both ways.
That's how she does it on the video - with a ch 1 to end off the crochet. I used to always ch 1 to end off but now I don't always ch 1 before ending my work.