Did you do well on your exams? I hope so!
I revisited this link http://www.porhomme.com/wp-content/u...cardigan-5.jpg
and noticed that it says "moss-stitch-cardigan" so I'm pretty sure a moss stitch is what you need. The right size needles with the wool/yarn (I think you use of "wool" where we use "yarn") should produce the desired result. It will need a tight stitch so the needle should be smaller than what is normally used, perhaps.
Your English is actually quite good, it's making sure we all are talking about the same thing that's important. You're ahead of me in languages, I only know English. I'm glad you checked back in, I'm hoping to know that you get this figured out. It's really great that you can help your mom this way.