I've trained 6 new people at my ex workplace. Apparently my boss liked my performance so she thought I could teach them best. She wasn't completely wrong. I loved training them, plus my co-workers hated the fact that they would have to train newbies.
Just be patient and be really nice to make her feel comfortable. Show them every little thing. For you it may be easy, but remember that she doesn't know these things yet. I always tell them to note down some stuff so that they can remember in the future, so maybe you can do that too. Let them work on their own a bit and assist them. Reassure her that it's okay to mess up at the beginning and that she can count on you. Trust me, many newbies need to hear those words.
I don't really have a funny story. Although there was this one girl who was always distracted and couldn't keep her head on her shoulders. It was a struggle for me too, because I wanted her to learn but she wouldn't. Everybody started being mean to her, my boss wanted her gone, and I did most of her part of the job so that she wouldn't get into trouble. I was babysitting her for like a month before she started to adapt. She quit the job 2 months in and in her goodbye mail she only thanked me for being the best co-worker she ever had
