R.K.
Dyslexia has nothing to do with intelligence. Both Leonarndo Di Vinci and albert Einstein were dyslexic. In out times jay Leno, Whoppi Goldberg and Tom Cruise are dyslexic. Tome Cruise to the point that he can not read at all. Someone has to read his scripts into a recorder and her listens to them until he memorizes his lines.
My oldest is dyslexic in the traditional sense and has difficulty reading however both my youngest and I are dyslexic in math.
My advice to you is to have her tested by an expert. In some kids the letters in the word don't just transpose, sometimes they appear upside down. Sometimes they transpose in a different order. Cat can become tac or act or tca or a letter could be upside down.
I know for myself that stress can cause my dyslexa to become worse. I also easily confuse left and right and if someone is giving me verbal instructions and is upset or we are running late also I will go left instead if right.
So it makes sense to me that a child taking a test or just has a bad relationship with a teacher could experience more trouble with dyslexia.