Honestly she sounds like a super unpleasant person in general. I've worked with similar people and I would honestly ask your store manager for a different trainer. You don't have to say she's being rude, you can just let them know her teaching style doesn't pair well with your learning style and you'd prefer someone with a little more patience, someone like the other coworker who helped you.

Barista here! It's only your fourth training day so no one should be assuming you should know everything by now. I had to be trained twice! It's takes at least 6 months on average to become confident on your own. I'm sorry you're having such an unpleasant experience with your trainer. Don't be afraid to ask another barista questions most of us have no problem answering them! You can always ask your manager if someone else can train you by saying her training style isn't best for you. Let her know you need someone who is a little more patient(which you deserve especially since you just started). Don't give up hope you will get there!